I did use Sevin Dust on my hens, thinking they might have mites, about a month ago.
I had to BUY a beehive to get bees for my garden this spring. $300 for the hive, an additional $700 or so for the stuff I needed for them, and a beesuit, and tools, then another $1000 for fencing so my neighbors don't get stung. I had to tend said beehive after dusting the birds. I also keep fish, which I have to tend.
I did not manage to pat them under the wings or the tail feathers, they were not cooperative. I live alone, so I couldn't get them in the bag to dust them. I did not have a respirator.
End result, before I could put my beesuit on or feed my fish I had to toss all clothing and shower, I have no idea how much sevin I breathed, the patchy feather area is on top of their heads were instructions said NOT to dust, I dusted it anyway... And today, a month later, they still are kinda patchy around their combs.
Tonight I sprinkled DE in their nest boxes and dusting area.
I used sevin dust for years on my chihuahua with no ill effect, but I KNOW what it does to bees and fish, so I believe that Sevin and I are through unless I am ready to give up my vegetable garden (which I need the bees for) and fishkeeping. I make my living keeping fish, so that ain't happening.
Gypsi