I've been in Australia and I've talked to the people producing the hive beetle control system using fiprinol. The Aussie Gov did the tests - and fiprinol was the most effective chemical to use against hive beetle. But, they are not dumping fiprinol into colonies - they are putting it in a trap, so that the beetle goes in, doesn't come back out. And the bees can't get in. So there in theory is no contact of bees with the chemical.
But, I also saw a presentation in Australia in which diatomaceous earth in beetle traps also killed beetles. Years ago, we found that volcanic ash killed insects. And if you are old as I, you may remember pesticides using dessicants.
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