You can try an oil that doesn't need to be repeated so often and has a more long term effect, like the castor oil. It's amazing how well it clings and doesn't wear off. And it has an insecticide action as well, so it smothers and prevents re-infestation. It can be found at any pharmacy and even at Dollar General. It also is working well for folks as a dewormer, so handy to have around.
The old scales will eventually fall off and new, supple scales will replace them if the mites are truly gone. The castor oil should do the trick!
Thanks. I'll look for that at that the store. I tried vaseline for a few nights but what a mess. I gave four hens a bath today to try and clean them up. Now I've been dipping in olive oil and blotting off the extra. I'll keep doing that till I get castor oil. I wanted something safe in case they ingested some.