So, after reading up here and elsewhere, we decided to do the Elector PSP method on our small flock for poultry mites. We have a mix of old and young birds who are free ranging most of the day, and may come in contact with wild birds (songbirds) in their foraging, so this made the most sense.
Expensive as heck, but a little goes a long way. One teaspoon to half a gallon of water, sprayed on the birds, bedding, coop and floor. We heavily sprayed their vents, under wings and legs, and then gently lifted and sprayed all around their head and necks to drench.
Eggs are safe to eat, may need to do one more in two weeks. Only toxic to mollusks, so must not pour anything down the drain. The girls tolerated their spas pretty well, and are happily preening in the sun. They'll get their favorite treat of melon seeds in a bit.
I'll post updates on how effective it was!