Yes, I stripped and treated the coop multiple times with both permetherin spray and dust, all corners, roosts, nest boxes, and cracks/crevices thoroughly treated.
PO is per os, by mouth, not sure why anyone would give frontline orally... This last link says nothing about topical/dermal application in chickens. I tend to not want to use chemicals on my chickens at all however I've had a severe northern fowl mite problem in my main coop and everything...