There have been a couple threads about cleaning/disinfecting coops. I recently responded to one, because the product being considered for use, was highly questionable. No, there was no disease, or illness being the reason for the cleaning.
There were such comments as "dry chickens are healthy chickens". No need to use anything but water, if there is no illness, or disease, etc. What a bunch of hooey.
One of the better, safer choices on today's market, is plain old Dawn Blue original dishwashing liquid. Remember all the pictures of it being used to clean the animals affected by the Alaskan oil spill?
Anyone that shows chickens, know they have to be bathed properly, mild soapy water (preferably Dawn Blue), a very diluted vinegar rinse to restore pH balance, and remove any soap residues, and followed by a plain water rinse, toenails cleaned, pedicures done, legs and combs get a thin layer of petroleum jelly, or bag balm, etc. This does NOT hurt the chicken when care is taken, and they don't get a chill. This can actually be beneficial.
Usually when it warms up in the Spring, I clean down my coops too. Because I don't want extra moisture during the winter, the coops, and roosts tend to need a cleaning in the Spring. Once again, I mix the equivalent of dishwater like you'd wash your dishes with, using water, and Dawn Blue original in a tank sprayer, and spray down the coop, including the wire. The roosts are wet down with plain water, then I wait a couple minutes, and wet them again, until everything is loosened up, and most of it is rinsed off. I then spray the roosts down with the dishwater solution, and use a stiff brush to clean the roosts. Once everything has been cleaned, it gets a final rinse. I even spray a light layer of the dishwater solution on the dirt flooring in my coop, and rinse it in good too. All feeders, water buckets, etc. are removed, and cleaned at the same time.
I try to do this, twice a year. I have found that keeping a clean coop, helps with preventing mite problems, spiders, mold, mildew, etc. Yes, sprays, and dust products are available to treat mites, and other bugs if/when they get out of control, but they are a lot more toxic than Dawn Blue. Yes, there are products for treating mildews, fungus, and other things, but once again, they tend to be much more toxic, and harsh. I find that keeping a clean coop, goes a long way as a preventative, so it's rare that I have to use anything else.
I think most of us on this thread are experienced enough to know the importance of keeping a clean coop, but wanted to post a reminder.