The oxalic acid question posed is actually kind of interesting for another parallel. I've got bee books that say if you have to kill a hive (AFB, for example) you can use soapy water. This was used in that New Jersey truck wreck a few weeks back after some of this forum's members had rescued what they could.
Since oxalic acid is used as a cleaner (Barkeeper's Friend among other popular cleaners), in theory it would be no more off-label as an insecticide than dishwashing detergent. However, I don't want either one in my honey. It really would be interesting to look at this a little deeper. Maybe dishwashing detergent is in the same class and it is improper to use it to dispatch bees.
A forum community dedicated to beekeeping, bee owners and enthusiasts. Come join the discussion about breeding, honey production, health, behavior, hives, housing, adopting, care, classifieds, and more!