I once had a collection consisting of about 80 adult snakes (along with babies and yearlings) and I've successfully eradicated mites. I have not had mites in several years. To rid them, I implemented the following process:
1) Keep the snakes in relatively sterile conditions - housed in a plastic shoebox with newspaper substrate, a water dish and a plastic hidebox.
2) Treat the snakes with Nix headlice treatment. To do this get a damp (with water) paper towel and put some Nix on it. Then coat the snake with the dilluted solution by letting the reptile crawl through the paper towel. Avoid getting the solution in the snake's eyes and mouth. Apply the Nix/water quickly - in less than a minute - then THOROUGHLY rinse the snake with water (Nix is poison).
3) Use Provent A Mite as directed to treat the snake's enclosure.
4) Repeat this process twice at three day intervals.
The method outlined above has worked very well for me.
Tim

Third Eye