I agree with Jay in that Nix is the best way to go. Though I owuld recommend that method. It's possible the snake might take some in while swimming in it, as well as that's jsut a little harsh to put the snake directly in the treatment in the form of a soak. Dilute 1 bottle of Nix shampoo to 1 gallon of water and put in a sprayer bottle. Remove water bowl and spray down snake and enclosure, replace water bowl when everything is dry.
As for reptile relief. We decided to try it instead of PAM as a preventative measure at work, and I can tell you the stuff is awful. I couldn't breathe at all! It was so harsh, it had us gasping and wheezing - and this was following directions closely. I can't imagine how it would be for those little snakies that have to live in there