I have started to learn that when you tell a child not to do something that just encourages them to do it. Judging from the feedback from my parents I wasn't too dissimilar.
So when Thomas touched the toilet brush while I was giving Lucas a bath I immediately told him to put it down. It shocked him a bit so he let go. However then he decided to pick it back up and was very interested in it and the brush in particular and started stroking it.
I told him to put it back and between bathing Lucas and juggling with the toilet brush I managed to get it back in the pot.
Then I had to explain to Thomas that he had to stand washing his hands until Daddy could come and help him so I could get back to Lucas.
This situation was stressful at all!