Every snake owner should have a can of PAM sitting around, it just is THE single best way to get rid of mites and other insects.
PAM got rid of my slight case of mites in about 3 days. Just make sure to spray the whole enclosure and follow the directions exactly. I usually wait till you can't see the spray on the container, then put then snake back in. As long as no odor remains and you can't see the liquid spray, it is safe to put your snake back in.