Thats what my mentor said he is using to control mites. He said he buys the cotton mop head re-fills, cuts them, soaks them in a food grade mineral oil, and then lays them across his frames.
He said the bees try to clean it out like any other foriegn material and thats how the mite are exposed. He said he's been doing it for years with no problems and that he picked it up from another guy with the same results. He also said shortly after his first year of trying it, he had his equipment tested by the local university and they found no traces of the mineral oil.
Anyone ever heard of this method?
He's a funny guy and says everyone he associates with in his bee club makes fun of him for it even though it works.