You will for sure have to treat again in about two weeks, when the eggs hatch, as the treatment will only kill live mites/lice, not eggs, and the eggs will hatch, and here we go again.
Hopefully they are running around from the irritation of the pyrethrins, and most of the critters will be dead in the AM. Pyrethrin will do that.
I know that a pyrethrin/permethrin mix kills lites/mice, but I'm not sure about just pyrethrins, as I haven't been able to find plain pyrethrins for several years.
I know exactly what you mean about feeling them on you. That is how I discovered they were there the first time. I used a pyrethrin/permethrin "poultry dust" and DE. Then I put DE in the litter, on the roosts, in the feed, in the dust bathing areas, and on the chickens (make a "powder puff" out of an old knee high.) This has given maybe 90% control. Somewhere on here I read that if you have chickens, you have mites. There are wild birds all around, landing on fence posts of the run, etc., so I can't stop the exposure. I can sometimes see a little sign of mites when I examine them, but nothing serious any more.