Sweet PDZ is a granular substance that was developed primarily for horse stalls. It absorbs moisture, trying out the waste and therefore keeping the odor down. I use it in our coop and it's awesome! I believe another name for it is Stall Dry. It's safe for animals. When we change out the litter in the coop (it's only 4' x 5') I sprinkle maybe a cupful around. As the chickens scratch and walk on it, it gets sort of stirred around. It keeps that coop smelling sweet for a month or more. We don't have poop boards, but if we did, I'd use it on them. DE is diatomaceous earth, yes. I put perhaps 1/4 c in with fresh litter and a wee sprinkle in their dust bath as well. It will absorb some moisture, but the primary purpose for me is to keep mites at bay. It's safe to ingest, but not to inhale, so I'm very careful about it and make sure it's well mixed in with either the litter or dirt so it doesn't billow and get inhaled.