I think damp paper towels would be easiest and safest. However, I tried switching my bigger pacman to paper towels and she (I'm assuming she, for right now), just completely shredded the paper towels and made quite a mess. I know Coco Fiber or Eco Earth is suppose to be highly digestible, but I still worry about impaction. I've since then been keeping Hasbro in all water. I know it's frowned upon, but she's kept in a small shoe box container with a UTH to keep the water warm and the water is shallow. When she poops I just clean the tub out and give her fresh water. It's a breeze to clean! She seems to be able to move around just fine, though it isn't much anyways being a Pacman. But, I've been thinking of picking up some eggcrate to put in the bottom to give her something more rigid to grip onto.