You usually don't put so much water that they have to swim. Just enough to have a very wet towel. I mist before sheds if I live in a dry climate or you can make a humid hide out of a butter tub with some damp moss inside and a hole cut in the side for him to go into it. Or, you can just drape paper towels in a tent and wet it down with a water sprayer every day until they shed. They usually will sit under it.