Amish Whitewashing: Mixing whitewash to paint the inside of the chicken coop. It's non-toxic, and kills bacteria & insects. It's not a paint, it's a water, salt, & hydrated lime solution that you apply yearly.
Using wood ashes for your chickens saves money. (fireplace ash only, not BBQ coals, etc) and when needed, mix 2 parts ash to 1 part sand for the chickens to do their dust bathing. It keeps mites away. That and paint the coop with hydrated lime.