Sounds to me like it's pretty saturated with crap. How long have you been using the same media?
Go to a pet store and ask for Reptile Litter which should be crushed walnut shells. It's the same stuff you can buy from the makers of the tumblers only at 1/2-3/4 of the price. My local store had 2 sizes, 10 and 20lb bags. The 20lb bag was the best deal.