Alfred, hope it all works for you, you need to get those mite levels down really fast, you are doing the best you know how, and I take my hat off to you.
One day through hygienic bees and so on, I would love to be not requiring any treatments to keep mite levels at an acceptable level. But that will take time, studying more, listening more, working more with the bees.
Of course, that is the game plan I would hope for all beekeepers, to become informed and be the best keeper of bees that we possibly can, with the least use of any form of chemical whatsover. But, there are times when we must treat if our colonies are in extreme distress because of mites, and I will probably never waiver from this opinion. Have a wonderful and beautiful day in our life. Cindi