I can tell you that MY father was given a set of colour pencils for the first time when he was young. He got in the habit of leaving them around all over the place. Slowly but surely they would disappear and my father would forget about them. His father, my grandfather, kept the same new box, would sharpen them. Then when next Christmas came, one of the gifts he received was a set of colour pencils in their original box and he was happy againMy father had an instant cure for his children not putting their stuff away.
He started when we were very young, with our toys.
When we left some out he picked them up, put them into a cardboard box and forced us to go with him to the local charity shop where he donated them for "kids who would respect owning them."
Noting, that our standard birthday/Christmas gift was 1 only hot wheels car, necessary clothes and a piece of fruit.
Let's face it, who really enjoys washing clothes or tidying up. Appears certainly not the younger ones LOLYour Grandson has a strong sense of being mathicaly correct in his desire to bring time management and expectation
to have everything under control and a
clear idea of what amount of time has to be allowed to complete his washing.
Then he can move on into some other type of activity. Probably one he would enjoy better.