To keep him from flushing the toilet excessively - and potentially save anything from getting flushed down and clogging the pipes - I recommend turning off the supply valve and flushing to empty the tank. It won't save electronics from getting water damage but without the payoff "woosh!" maybe he'll get bored and move on.

As for the drinking, try to redirect him to drink from the sink nearby either before or after using the toilet (appropriately.)

Here's another thought: my 12yo has historically been obsessed with water play. For a long time he was fixated on toilets like yours is - and he still is somewhat - but by disabling the toilet as above and giving him the opportunity to use water in more appropriate ways (bubble baths, hand washing, dishwashing) he's not nearly as obsessed with the toilets in that way.

This is a gamble, but I taught my son about germs. We looked at pictures of various "germs" after they'd been under a microscope, read a book about Louie pastuer, etc. He's easy to direct now (of course he's eleven too) because he read about dysentery and nasty stuff like that. It also helped me keep him from putting his fingers in his mouth, his mouth on the cart, drinking others drinks etc.

I am sorry to hear that yes it can be a phase and all I can say I pray it pass over. My 8 yr old was eating his poo when he was 6 and we was told that not to over reacted because he was looking for either bad or good. But that is easy said then done. We would tell him no eat when he did it and gave him food to eat in place. Now itbis paint and string.

Folks. This is PUBLIC toilets as well as private. No control of public. And I can't carry cold water everywhere. But thanks for the ideas

My grandson had a facination with the toilet for awhile there also and it is a phase. As for the drinking, have you tried giving him one of those wacky straws where their drink goes all over the straw before it gets into their mouth. They like to see the water or drink travel....just an idea....