I occasionally put thyme in the smoker when I check the bees. Just smoke as usual.
Then when I do my accelerated powdered sugar count, the number is always higher, then not putting thyme in the smoker.
I don't know if it could be used as a form of mite control, I just figure if a few more drop then normal its a good thing. Also I wouldn't want to over do it, as I don't know if too much would irritate the bees.