Everyone here seems to be adult. Every one makes just what he wants. But why he gather support their makings with "disinformation". And why they doom others doings? - Nonchemical beekeeping. I think that many have passed his chemistry lessons in shool.
finsky, you know i'm not one to jump on the "organic" band wagon. most of the things that people are doing are either unproven, or proven to be ineffective. however, the powdered sugar, as a mid-season way of knocking down mite numbers makes sense. for those of us who have been using it, and in the few limited studies i have seen, it seems to work to keep mite numbers down. anything that stimulates grooming, by default reduces mite numbers.
even i have a longer season than you do, but chemical treatment in the spring would not be practical. i have to wait until fall if i want maximum honey production. if i do that, i may have such a high mite count as to put my hives at risk. by using the powdered sugar early and often, i can keep mite numbers down and not lose time for honey collection to chemical mite treatment.