I really suggest giving them a "butt bath" until you figure out what your using to treat them. I would give them a bath once a week and every day you don't give a bath spray them with neem oil.
If you don't have any permethrin right now you may want to give them a butt bath. Most of the mites should be around the vent, as well as the eggs. Just get her bottom wet and then put some dawn soap. Giving them a "butt bath" really helps get off all the mites temporarily. Giving a bath would...