How to clean properly

[Lemon]

My hamster Icicle has gotten herself sticky with what I think is pee. I didn’t see her do it and she usually has a separate bathroom corner.

I want to clean her but I heard many times that water is bad for hamster skin. Should I maybe let her go in her sand area or will she take care of it herself?

Other than this she is very young and healthy, just a little dirty.