I use Forest Floor cypress mulch substrate. I have always been happy with it.
Also check out Reptile Spray. Its sold at Petco for about $8, it will clean anything and can be used directly on your snake. I Have only had mites once but Reptile Spray killed them in one treatment in less time and for less money than PAM.
http://m.petco.com/product/109610/Na...ile-Spray.aspx