ive had a iguana die from mites before because i took him to the vet to late alot of home remedys dont work trust me i tried everything sprays, baths , cleaned his whole tank with water and some bleach and even got rid of all his logs and bedding ect. youd be better off taking him to the vet for a skin scraping so you can find out what type of mites he has. it only cost me $75 for my iguana so a frilly shouldnt be to much more(depending where you live or the type of vet you go to). Best of luck with getting rid of those stupid mites.

also note that you can bring mites into your house if you live by a woods and if you have a cat or dog they may be able to bring them in your house as well. < Vets advice that i got.