Powdered sugar is all I use, I think it has worked well.
I usually do one treatment after they swarm or treat all the splits at the same time (march/june), nothing until end of jully then I do two treatments ten days apart and the last one I do after all the blooms are gone and usually a good few days after the first frost.(Indian summer, late Oct. to mid December)
I used to try and shake the sugar on the frames, but the girls didn't like that too much so now I use an old screen from an old storm window.
I open the hive, plop the screen in place of the inner cover, dump the sugar right in the middle and with a bee brush, I spread it around sort of evenly.
Then I'll take that screen off, put the inner cover back on, remove the hive body that was treated and do the next(bottom) hive body the same way.
That, and screened bottoms, I keep the mites in check pretty well. The most important treatment is the one going into winter, the mites are not in the brood, there is no brood then, they are all on the bees...
This year 7 out of 7 surviving so far...