Chickens mites and lice

Poor Mister Quincy and a couple of the hens have been suffering with mites/lice this summer (partly the reason why we replaced the hen house). We've been treating them and the house with diatamaceous earth, but Quincy hasn't been responding as well as we'd hoped and started losing feathers, so a few days ago I netted him (not an easy job) and we gave him a detailed check up. Beneath his feathers he was overrun with mites and lice so we've pulled out all stops to treat him.

We've been spraying him (and some of the less infested hens) with a mixture of garlic juice, water and essential oil every three days and giving him extra rations of iron rich foods (in particular scrambled eggs which he loves). We've also started putting garlic in their water - apparently a useful deterrent.

He seems to be responding well but the war with the parasites is not yet over!