Me too its been awhile since I used sulfur. I used the stuff in Wood Duck boxes for twenty years. I never saw a mite one in the houses are on the birds. I'm gonna get some & use it. I never put a lot just poured some in the corners of the houses & added shavings. I cleaned all the houses out once a year & added sulfur & new shavings. Someone mentioned it wasn't a good idea. I beg to differ I did this forever with not a problem. If it worked then it will work now.Around here, the big chain pharmacies don't carry Flowers of Sulfur any more because they've all gone "big business" and they don't carry it if they can't sell it all out in a week. So I got some in the gardening section. Gotta be sure to get the "dusting sulfur" or "wettable sulfur" though cause the soil type is granular. (I didn't get it for mites though, I got it for another reason.)
Note about my "big business" comment: Back when I was young, in the Stone Ages, stores carried what customers wanted, even if they didn't sell but one box a year (assuming it was something that would keep for a good while). I sure do miss that way of merchandising. It made for a lot of stuff not being Factory Fresh but when it's something like sulfur, so what?