Dishwasher mistakes costing seniors hundreds and the unexpected items safe to wash inside

After a lovely Sunday roast with the family, there's nothing quite like being able to load up the dishwasher and let it work its magic. But if you're like many Australians, you might be making costly mistakes that are not only damaging your kitchenware but also adding unnecessary dollars to your bills.

Research shows that 58% of Australian households own a dishwasher, yet many of us are using them incorrectly - and it's costing us dearly. From ruined cookware to inflated energy bills, these common errors can hit particularly hard for those on fixed incomes.

The expensive mistakes you're probably making

Your quality kitchen knives

While steel and ceramic knives won't tarnish in the dishwasher, the heat can make the blade more prone to dulling. It's better to wash them by hand to avoid having to sharpen them more often – and it will ensure they last longer and stay in great condition. Given that a decent set of knives can cost several hundred dollars, protecting this investment makes financial sense.

The same principle applies to blender blades, which can dull over time and make your smoothies less smooth.

Wooden items are dishwasher enemies

Wood is a natural, porous material that doesn't take kindly to the intense heat and moisture of a dishwasher cycle. The high heat will cause it to splinter and split, and any cracks are ideal breeding grounds for bacteria.

To keep your wooden cookware in top shape, hand wash with mild soap and water and dry them promptly. Avoid submerging them in water for a long time. A quality wooden chopping board can cost $50-100, so this simple care tip protects a valuable kitchen investment.

Non-stick cookware needs special care

Non-stick pans should be washed and dried by hand, as the dishwasher can wear down the non-stick surface over time. Your next omelette could be stuck to the pan if you don't stick to this advice. Quality non-stick cookware can easily cost $200-300, making hand washing a small price to pay for protection.

Crystal and delicate glassware

If you take all the right precautions, you can wash crystal in a dishwasher, but we wouldn't recommend it. Over time, abrasive detergents can mark and scar the crystal. Full-lead crystal is less dense than glass and scratches easily.

For those special pieces inherited from family or purchased for special occasions, the risk simply isn't worth it.

Metal cookware that doesn't play nicely

Copper pots and pans can lose their lustre in the dishwasher, while aluminium can turn black and cast iron can rust. Cast iron detergents can strip away the seasoning that gives cast iron its non-stick properties, and the moisture can lead to rust.

If you're not sure about a particular item, err on the side of caution and wash it by hand—especially if it's a prized Le Creuset or a family favourite.

Insulated bottles and travel mugs

The vacuum seal in insulated mugs and bottles is what keeps your drinks hot or cold. The dishwasher's heat can damage this seal, leading to leaks and poor insulation. Quality insulated bottles can cost $30-60, so it's worth checking the manufacturer's guidelines first.

Pressure cooker lids need special attention

While the actual pot of a pressure cooker can go in the dishwasher, a lid should always be hand washed. The high heat and water jets could damage the seal mechanism, making the actual pressure part of your pressure cooker obsolete. More concerning, it could make using your pressure cooker dangerous if safety mechanisms are compromised.

The surprising items that ARE dishwasher safe

Here's where it gets interesting - there are plenty of household items you might not have considered that can safely go through a dishwasher cycle, potentially saving you hours of scrubbing time.

Personal care items

You can wash hair and makeup brushes in the dishwasher to remove bacteria, makeup and buildup. Most cosmetic tools like nail clippers and tweezers are dishwasher safe. You can even wash plastic makeup brushes.

Your hairbrush can hold almost 3,500 colonies of bacteria, according to University of Arizona research. Remove any stray hairs and drop your brush in the silverware tray for a thorough cleanse. Just remember - only plastic brushes, not wooden or boar-bristle ones.

Cleaning supplies get a clean

Clean your cleaning supplies — plastic or metal dust pans, vacuum attachments and washable filters, for example — in the dishwasher. Place smaller items, like vacuum attachments, in the top rack. Larger items, like a dustpan, can go face down on the top rack.

The shelves in your refrigerator can get pretty dirty. But you can easily clean them in the dishwasher! Just remove them and put them on the top rack. Make sure to use a gentle cycle, and you should also double-check your manual to make sure they're dishwasher safe.

Kitchen odds and ends

It's easy to forget about cleaning the plate in your microwave, but it is essential. Lots of soups and other microwavable foods can bubble over, creating a mess that should not be overlooked. Your microwave turntable plate can go right in the dishwasher.

Stove knobs are one of those areas in the kitchen that tend to get greasy very quickly. Instead of painstakingly scrubbing off specks and smudges by hand, simply pop off the plastic components and wash them along with your dishes.

Children's items and toys

Germs can linger on your kids' toys for months. Disinfect them by putting them in a mesh lingerie bag on the top shelf of your dishwasher. Then just let the normal cycle run.

Babies are notoriously messy, and their toys can get pretty dirty. But you can wash many of them in the dishwasher! Check for a dishwasher-safe sign, and if you see one, you can go ahead and wash them.

The pre-rinsing myth that's costing you money

Here's a revelation that might surprise you: rinsing your dishes before putting them in the dishwasher actually won't make your crockery any cleaner and will just waste water.

Dishwashers have special sensors that measure how much gunk is coming off your plates during the wash cycle. A pre-rinsed plate can 'trick' your dishwasher into thinking it's cleaner than it really is, and the dishwasher will respond by dialling down the power, so your plates could come out dirtier, not cleaner. The best approach is just to scrape off any solids into the bin and just let your dishwasher get on with doing what it's designed for: cleaning your dishes.

The water waste is staggering. Scraping food residue from dishes instead of rinsing can save significant water. Rinsing can waste 2.5 gallons of water per minute, and most new dishwashers don't require it. You waste 6,000 gallons per year if you insist on pre-rinsing, Consumer Reports says.

For perspective on Australian usage: A standard, energy-certified dishwasher will use around 11 litres of water per washing cycle. Older appliances can waste up to 37 litres per cycle, while those built after 2013 tend to use around 18 litres. Compare that to washing the same amount of dishes by hand in a sink, which can waste up to 100 litres of water.

Australian seniors: your energy-saving advantage

If you're over 60 in Australia, you have access to some excellent energy rebates that can significantly reduce your dishwasher running costs.

The NSW Seniors Energy Rebate is available for eligible independent retirees to help cover the cost of their electricity. To be eligible, you need to hold a Commonwealth Seniors Health Card. From 1 July 2025, the NSW Seniors Energy Rebate amount is $200 per household per financial year.

Similar rebates are available across Australia, with the NT Seniors Recognition Scheme offering up to $500 per year to help with electricity, gas, phone and internet bills, as well as fuel, travel, and accommodation expenses.

The energy rating on dishwashers ranges from 1 to 6 stars. Every extra star could save you 30% on running costs. The more stars, the more energy efficient your dishwasher will be, and the lower the running costs.

The cost of electricity makes up the largest portion of dishwasher expenses, costing between 11.9c and 26.8c on average, per load. The amount of electricity used will depend on the size of the dishwasher, as well as the energy efficiency star rating.

Smart loading saves money

Running a half-full dishwasher will use far more energy and water per plate than running a full load. Plus, a half-full load won't dry as well as a full one. That's because the plates hold heat from the wash, and that heat is what helps the water to evaporate, leaving you with dry dishes. Fewer dishes mean less heat, which can leave you with wet dishes at the end of the cycle.

However, don't go to the other extreme. While shoving everything into the dishwasher seems rational because more gets cleaned at once ,it isn't the most effective method. Badly stacked items can block the dishwasher jets and detergent and you may find yourself re-washing things. If you stack with space between your dishes and cutlery, water can reach every surface and you'll get a more dependable wash every time.

It costs less to repair new dishwasher models because their parts are much easier to find compared to older models. If your dishwasher model is quite old and worn down, consider purchasing a new model instead.

The cutlery controversy settled

It's the domestic dispute that's raged since the dawn of the dishwasher – should your cutlery point up or down in the basket? Some argue it's up, up and away for a better wash, while their opponents play it safe and go down all the time. And then there are those who choose chaos and put them in any which way. There are pros and cons for each side, but our experts say down is the only way to go.

The safety argument wins here - sharp knives and forks pointing up pose a real injury risk when unloading.