I agree, sponges are nasty. I wouldn't use one. I know a lot of them come with soap stuff already in them. Have you ever noticed when you use a brand new sponge it feels slimy almost? Then when you get it wet its soapy. I don't think that would be healthy for your leo.

I would just use a container with a hole in the top. I personally use papertowel. Never had a mess with it. Then just change it out every couple of days.