I'm sure it would be useable the same as carpet would be. Easily washable too. Problem is that fleece doesn't absorb liquid terribly well (it usualyl pools up or runs off before finally being absorbed), and because it is so light/soft, it's just going to get pushed around and not really act much as a substrate. Sure it's washable, but I don't think it would be more convenient than any of the other options out there. If I were to use any sort of cloth, I'd want something that maintains it's structure a bit better (think burlap/canvas) but also absorbs waste so that the snake it not cruising around in it afterwards.