Adrian Quiney, a beekeeper in Hudson Wisconsin, appears to be able to successfully control mites WITHOUT chemicals. He uses what is called the dutch/german drone brood varroa control method in June. Later in August he splits his hives and overwinters his bees in double deep five frame nucs. So far this winter he has had outstanding success with a 87% nuc survival rate through the end of February. I can't think of a single ECWBA member that wouldn't like a survival rate like that.
Here is a link to a YouTube video describing the Dutch/German drone brood varroa control method.
Here is a link to his February 27th inspection of his nucs.
Follow this link to see his moisture control method for overwintering nucs.