I am fighting this battle right now. Found a mite crawling on an egg on Wednesday. Up until that time I was (I am ashamed to admit) unaware that we even had a problem. So I decided to tackle it in steps. I hope this information helps you....don't know if you'll need it after the acid bath but there may well be a next time. Mites are so persistent that I'm not sure even the acid wash did the trick, aside from corroding and causing folks worry. So let's get on with it.
Step one. Put away the brick cleaner and reserve it for jobs where it's needed. It's not needed here. Get a piece of paper and a large margarita, preferably with lots of salt around the rim of the glass. Drink the margarita and stare at the paper hoping some brilliant idea will come to you. It seldom does, but at least if you have the paper in front of you while you're drinking your margarita it LOOKS like you are busy.
Step two. Pour over all the information on BYC and find the stuff that is doable for you and your situation. Weed out the other stuff, but it's critical to understand that to get a handle on this problem there just aren't any shortcuts. That was tough for me to swallow. Another margarita helped wash it down. Then get out and gather the materials you'll need so you have everything at hand when you're ready to start. Of course, this will also involve grabbing a nice lunch while you're out shopping. See? Nothing to this mite control stuff so far, is there? In fact, up to this point it's been rather pleasant.
This was my shopping list, if this helps.... 2 cans of Permethrin dust, 1 bad of powdered garden lime, (make sure it's garden and is NOT hydrated lime) 1 package of face masks, 1 pair of gloves that can be pitched after all treatment is done, 1 bottle of Neem Oil and a sprayer to use with it. You may, if desired, add a couple of cans of liquid courage...I chose Bud Light because I'm watching my figure. (Have to watch my figure since I can no longer see my feet.)
Step 3. Get the chickens out of the coop. If you have to cage them, do so. If you have a nice run they can use while you're working on the coop, so much the better, or you can let them free range, knowing full well that they'll have to poke their beaks into the coop to see what you're doing in there from time to time. Put on those gloves and that annoying face mask. Remove old bedding and nesting material. (I know, I know. I hated that part too, especially since for the first time I had Deep Litter that was actually working properly.) If you can remove the nest boxes to clean them as well, even better. When you get the coop stripped down to parade rest, everything out, from the feeders, waterers and materials to roosts, it's time to clean. We have a power washer and painted walls in the coop, so that helped shorten the job tremendously, but even a hose with a pressure nozzle will help break down the dust and force some of the mites out of hiding.
Hit the roosts outside with the water first and then stand them up to dry while you go inside to work on the coop. Hit the walls, the studs if they are visible, behind and around the nest boxes, all corners and places where the frame meets the bottom edges, and wherever your roosts were supported. You want that chicken dust out of there and a bare surface for the Neem Oil. Leave the coop as open as possible to air out and dry. It will not dry out completely - at least mine didn't because I have a dirt floor. But once the big puddles are gone, mix up the Neem oil per package directions, adding just a teaspoon or less of dishwashing liquid to help as a surfactant for the Neem Oil. Start spraying every surface you just washed. Make sure that it gets down into any wood joints well, and along the edges and corners of the coop. Pay attention to the area around where the nests and roosts are installed. NeemOil the roosts outside as well, getting a good amount in the ends where the wood is porous. Then hit the floor with a good, even layer of the lime, making sure to get those corners and edges. That will help dry the area and keep it from smelling, as well as be a total irritant to any mites that are down there. At this point you can also put down some of the Premethrin dust in the corners as well, and if you're feeling really disgusted with those darn mites for making you work so hard then hit the areas where the roosts will sit too. Put down a thin layer of bedding on the floor right over the dust and the lime - I say thin because you're going to have to repeat most of this in another week or so, so you want to make the second time go a little faster and smoother than the first. If you have cleaned everything that you took out of the coop, you can now put it back. Put fresh nesting material into the nest boxes, and if you want to add a little DE in with it you certainly can. Personally I'm in the camp of "would rather not risk the respiratory issues" but I did it because I figured they aren't in the nest that long anyway and if a little mite wanted to take a bite of my girls he'd have to get through one more layer of protection first. I also dusted the underside of the roosts and the ends with some Permethrin just because those doggone mites made me so mad. Was it necessary? I dunno. But it made me feel better!
After dark it's time for the chickens. Yep, after dark. We have 28 of them and waiting until they were roosting made this job go so much better. Besides, the mites feed heavily at night so why not wait until the girls were wearing the maximum number of mites for the direct Permethryn attack? We have a flashlight that we wrapped with a blue washcloth, rubber banding it into place to dim the light and create enough light to work by but not enough to wake up all the chickens. Fill an old sock with your Permethrin Dust. Grab a chicken off the roost, hold him/her upside down so the feathers hang down and the bird calms some, then pounce that dust onto the bird, using the sock. Get the vent area and under the wings - this will be easy because you are holding the chicken by the feet so those areas are well exposed. Dust it well, then put it back on the roost and grab the next one and keep going until all the birds have been dusted. You'll probably have dust left over in the sock, and that's fine. I just dropped it into a plastic grocery bag, tied the flaps shut, and put it away to use next week. That's it. You're done.
Step 4. Get those clothes into the wash and hit the shower. Here we drew straws, and I got the short straw so Ken got to shower first. But I just waited until I thought he'd had time to wash well, then turned on the kitchen faucet's hot water. He relinquished the shower to me right quick after that. In fact, I wasn't even finished with my celebratory margarita when he came out.
I know it seems overwhelming. It did to me too, but I had to decide if I was going to try short cuts or get it done as thoroughly as possible the first time. I had to break it down into little bites to be able to swallow it all. So that's what I did. By the time we were finished I ached in places nice people don't talk about, and I felt grungy and crawly and yucky. But when I went out to the coop this morning everything was so fresh and clean, and the girls were all just fine. I'll repeat the Neem Oil, the dusting, and pull that latest batch of litter (which is why I put down just a small amount) out of the coop and hit the corners and edges again before putting fresh down. After that, we'll begin a preventative program of routine maintenance that not only includes the things we've always done, but also adds some extra mite protection at the same time. So it adds another 15 minutes to the housekeeping routine....that's still a heck of a lot better than giving up an entire Saturday to do the coop and girls and Sunday to tackle the run and repeat the process in a week.
Added note: We think we found the culprit - everything was fine until the last batch of straw we brought home to use in the nests. Ken went to get some fresh straw from the broken open bale and spotted a mite on the baling twine. Oops. That's kind of where I thought our problem came from but when he saw that this morning we are now pretty sure that was the start of it all.
LISTEN TO BLOOIE!!! Amaaaazing lol.... You rock Blooie
Margaritas and shopping..... Best solution so far