If he is chewing threw the bottles get him a bowl like that ^^ he can't tip it over it's too heavy. If he gose in (which he likley won't) then he will realise there is water and get out. They aren't stupid and won't sit there in something they don't like. The chances of them getting sick from going in the bowl are very very slim. And the chances of him going back in the bowl if he fell/went in are also slim.

Well, I'm not sure if this will help, but try and tape is over???
The water would go right threw it.

We have always been told by our pet shop not to put bowls with water in with rodents- They can grab the side of the bowl and lean on it and it moves and tips all over them.
That's why you get a heavy bowl that they can't tip over. And FTR don't belive everything your pet stores tell you they usually know nothing about animals.