I always used Borax to soak my babies nappies in. Came up beautifully white. Never had a problem. Mum used it to soak my nappies. I’m almost 80 now and doing well. My kids are both in their late 50s and are very healthy. Both had a couple of kids of their own.
I get all my air conditions cleaned and serviced every year. Living in North Queensland it is a must. Mine get used 24/7 throughout the hot humid summer months.