Just learned that the stuff you use on kids for head lice... Is permethrin! Way cheaper and easier safer than mixing my own concoction. Haven't tried it yet, not even sure if there's an active mite issue, but I'll add it to my chicken kit. Anyone used it? NIX spray is what I saw in the store.
I bought permethrin at the feed store and dust any new incoming pullets in quarantine -- but be careful not to get the dust flying everywhere -- respiratory issues for people/hens.