The way I treated my snakes for mites was:
1.) Took everything out of the tubs
2.) Bleached everything
3.) Put new bedding in the tub
4.) Sprayed the tub, bottom of the water dish (not inside - just flip it over and spray lightly) and anything else you put in
5.) While the setup is drying I coated my snakes in olive oil and let it sit for about 20 minutes
6.) Wash snakes off using mild soap (I used dawn dish soap)
7.) Put snake back in if everything has dried from being sprayed
This worked really well for me. I did spray my tubs down about 3-4 weeks later just to be on the safe side but I haven't seen a mite since I treated for them. Also instead of using the olive oil you can soak them instead to get the mites off of them. You will need put a little soap in the water though to break the surface and ensure the mites drown.