I'm using paper towels -- they're new snakes and although I trust the folks I got them from, I wanted to be able to watch for mites and stuff (so far so good), so white paper towels seemed like the best choice.

I've been trying not to disturb them since we just picked them up on Saturday (well, as much as one can "not disturb" snakes when you have to take them out in order to melt additional ventilation holes into their environments and so forth), but I did check the paper towels and I didn't feel they were wet. I'll still change them out this evening in case I missed something.