We've been keeping chickens in an airy run which houses 2 wooden coops, one of which has a felt roof. The coops have been in use 5 months. The pooh on the floor of the coops is removed every day, so they are clean apart from the pooh stains. The nest boxes etc are all made of plastic and cleaned regularly, and the straw in the boxes is replaced regularly as well. The hens are all ex-batts and never wanted to perch, so there are no perches for mites to hide under.
Although the chickens don't appear to suffer from lice or mites, since I have spare time this week I was thinking of treating the coops just in case there's an infestion around the corner - quite literally, as one of our neighbours has just sprayed his coops, which makes me wonder...
But what products work best and should I use (or not)?
I decided on spraying Poultry Shield all over the coops and in every nook and cranny. But how long do we have to wait until the chickens can use that coop again? Just until the wood is dry later that same day? And do you need to disinfect the coop as well as use Poultry Shield?
Once you've used Poultry Shield, would you need to apply any mite or lice powders as well e.g. the Barrier brand products? As our hens don't seem to have lice or mite, I would imagine I can just let them walk back into their treated coop without having to dust them with anything?
Then there's diatomaceous earth, which I was going to add to the dustbath. As the ground of the run is compacted soil, shouldn't this be dusted with diatom powder as well? Especially since I'm planning on covering the ground with mulch to stop us from slipping in wet weather, and mulch may well harbour all sorts of things after some time. And how often should this be repeated?
Just thought I'd ask, prevention being better than cure, and all that

I could do nothing at all until I'm certain there are lice or mites present, but then it'd be sod's law that I'll be very busy at work and the weather will be foul