Mites made their way into my collection for the first time this year and now I fully understand all the frustration that I have read in other post. Due to health problems, asthma, I cannot use strong smelling sprays like black knight, etc. What worked for me was soaking, first warm water for a few minutes then add in some soapy water and soak. Depending on how many mites are on the snake, I have soaked with soapy water from 1-6 hrs. Start with 1 hour. Then go to your local drug store and buy Nix. It's a head lice treatment and you can buy the big name brand or the house brand, Savons, Clarks, Eckerd, etc. The house brand is just as good and less expensive. Mix one ounce of this into a quart of warm water. Setup a sterilite or rubbermaid box, paper towels only, spray the sides and bottom. Now spray a sponge or small rag with the solution. Remove your snake from the soaking tub, wipe him down using the soaked sponge or rag. The next day, spray the snake and box but be sure to remove the water bowl. You can return the water bowl after an hour. Repeat the process of spraying and wiping down the snake every other day for a couple more treatments. Now just monitor the snake and box. Open the container every day, check the lid, under the paper towels, on the snake, and spray if you see any mites. You probably will not see anymore but keep the snake out of your collection for at least another week.
Good luck