I think it might be more suitable for use on walls, rather than in the coop, being caustic and very messy, as Dinosaw says. The trouble with anything you use in a coop is that, if fully effective against the mites, it renders the coop unuseable for the hens for quite a long time. Creosote is usual inside wooden coops, but takes ages to dry out and has poisonous fumes as well as being sticky when wet.