Hi Donna. Being in the UK, I have no idea what a rubbermaid bin is! So that's a question for our US members.
On the question of wooden water bowls, I guess that would depend on what has been used to seal the wood. You wouldn't want anything that might contaminate the water. I would also guess that it would be more difficult to ensure that the bowl was totally clean, unless the wood is particularly smooth and well finished.
Personally I'm not convinced that freezing is an inhumane method of killing pink mice. That has been the subject of much debate previously.
