I do not "believe" ppete is right, but that does not mean I am right either.. From everything I have read, watched and heard, OAV is benign/harmless to the bees. So I would like to see some data? Some research? Anything that states what he just did? I do believe OAV is a magic bullet..
OA Dribble is MOST definitely not a magic bullet, it damages the bees because they ingest it;
Do not be in the “If a little’s good, a lot would be better” mentality with oxalic. It (drench) can be rough if over applied to the winter cluster, and is rough on the brood in the summer colony. However, be aware that most other treatments also affect the brood (amitraz, formic, thymol), queens (coumaphos), or drones (fluvalinate).
But as stated, I have yet to find any reference to problems the OA vapor causes the bees?? In some of the studies they treated bees every week for three months and they showed no ill effects what so ever. If the OAV harmed bees or brood wouldnt being treated so often have wiped out the colony hands down? Much less left them mite free and thriving?
From Randy Olivers site;
Radetzki didn’t note increased bee mortality after winter treatment. Heinz Kaemmerer of Heilyser Technology Ltd. says: “We treated several colonies for 3 months during winter, once a week with the vaporizer and all colonies survived.” “With brood, colonies can be treated with the right amount of OA 3 to 4 times, a week apart; there is no harm to bees, queen or brood.” Medhat Nasr confirms that vaporized oxalic is very gentle to the bees.
It is good to know if what you are doing has risks. I have not found any for OAV Yet.. I have seen other statements that claim how "bad" OAV is, both for the beekeeper, and the bees, and so far they have all been pretty easy to disprove through researching.... That does not mean I am right and OAV is the golden ticket. It only means I have not found (or seen) any concrete evidence to that claim. Entirely possible since some information comes from people who have a vested interest in OAV being a good thing.