I'm following the manufacturers instructions. http://www.apithor.com.au/how_to_use_apithor.html
Have you used them?
Manufacturer advises no residue if used as instructed.
Bloody beetles are giving me the gripes! They aren't sliming me but they are there in large numbers.
I think part of the problem is that I have had two triple 8 frame full depth hives & I have had a peek inside during winter & have noted lots of bees & honey in the third super however I didn't realise that they had left the bottom brood box leaving room for the beetles.
Single super hives in good condition don't have as many.
We have warm weather here & the bees & beetles go all year round. It is the end of winter here & there is plenty of brood but no drones.
All my hives are level & sloping slightly to the front so drainage shouldn't be a problem.
I'll get the hang of SHB eventually.