I recently had a mite problem. I asked a local reptile store what they used to treat it. Provent-A-Mite. I bought some and it worked great!
Provent-A-Mite is strong stuff...make sure to follow the directions and don't spray it directly on your reptile. Don't have the reptile in the enclosure...let it air out afterwards for a half hour. It can be used to kill and prevent mites and tics. With many other treatments the mites seem to come back. I used Provent-A-Mite and haven't seen one since that day. It runs about $25 for a can...but you'll never have to worry about mites again...the can will last you years and years.