I use Colombine spray - insecticide for from boddy and ridewood for real strays, and occassional spot use for the birds.This deals with feather lice, tail bone lice,fleas, ticks and red mite.
Otherwise I use jeyes fluid to the correct concentration for the loft.
I always have a mild solution of garlic both in their drinking water and bath water. And get 'ivomectin?' (was a dilution of sheep dip I believe) from the vet 'spot on' treatment annually.
So far not had a specific problem with red mites.