What type of enclosure is he in? How are the temps, ambient and warm, cool side? Humidity? I wouldn't soak him to remove the remaining skin. The damp towel is ok having him crawl through it. Consider using a high humidity substrate like 100% cypress mulch mixed with Aspen or care fresh. Usually after a bout with mites a snake will be mildly dehydrated or may suffer with inappetance. Just make sure they have fresh water in their bowl. The appetite will return. Don't forget to retreat for the mite eggs that hatch 3 to 4 weeks later. Good luck. Use the search bar here on the forum to get the directions for proper eradication of mites. It involves quarantine, cleaning and disinfecting and retreating.