I used retile carpet for over a year on my leopard geckos, here is what I did: I would spot clean poop everyday, then once a week take it out and rinse it with HOT(as hot as you can get it water). I always had 2 so I wouldn't have to wait for the one to dry. Then after 6-8 months I would replace it. Some people ran it through a cycle in the washing machine (just hot water, no soap) but after a couple times it would warp. You could also take a spray bottle with a few teaspoons of vinegar and water and spray the reptile before you rinse it with hot water, just make sure it's rinsed well. I eventually just switched to tile.