I took 2 cups of powdered sugar, pulled out each frame, and using a food paintbrush, I sort of painted dry powdered sugar on the bees. Needless to say I wore a full suit, boots covered by elasticized suit legs, and nitrile gloves tucked into my elasticized sleeves. The theory is while they are grooming off the powdered sugar they also remove the mites. I think it does not get the mites in the larva. But when I did it the queen was barely laying, so maybe I'll end up with healthy bees. Oh, my sbb has a sticky board, I had it clean of sticky when I powdered the bees, and then counted and cleaned, with a plastic scraper, and warm soapy water, for a few days afterward.
I have had bees since March. I started Keeping them at the end of July, after I lost my initial hive to not opening the lid, having them in shade, the dearth, etc. And no idea how many pests they came with when I got them. I am a determined student however. Trial and error with plenty of error I am afraid.