One other thought on the Bee-Go problem.  You mention that there was a lot of burr comb present.  Occasionally in such a situation I also find Bee-Go not very
effective, and I have always considered that the burr comb forms a barrier to the fumes.  Since it cannot go through the comb, bees below are not exposed to the
fumes, and thus don't move.

Ted Fischer
Dexter, Michigan USA