There is a highly controversial theory ant keepers have had with dealing with mites. Lemon Therapy. Essentially putting slices of lemons to deal with mites. Now, don't ask me how this works. I have no clue. Also, freezing stuff can effectively kill them, but some mite species can withstand temperatures below freezing. Extreme heat like baking or boiling also works with sterilizing substrate and whatnot. And then there's cleaning everything with alcohol and bleach.