Keeping them contained in the infestation area. Your coop is a sanctuary for your hens but also for parasites. A double edge sword. We just controlled them with Sevin 5%. Then DE'd the coop. Now that I mentioned Sevin, I am going to be attacked.
Sevin is a dirty word. Time to put my catchers mask on. Good luck with what method you choose. But you will only win the battle, not the war.
Neem has eliminated my infestation so unless some pesky birds or rats manage to break in again to re-infect them I think I'll be alright, but I'm definitely checking frequently as they are such a nightmare to get rid of. It's at least a month since I painted the coop and not even the spiders have returned. I can't find any evidence of mites and I know where they hide! My run is also completely covered by a solid roof so no wild birds can sit on the top and share anything that way.
My original girls had lice once from sparrows breaking into their first little run but once that was fixed and I'd eliminated the problem I've never seen a trace of lice again in more than three years, and they do get checked regularly. Without exposure to a host my girls can't be re-infected, and once the lifecycle of the parasite is broken they can't come back without hitching a ride on a host.