Hi, I'm new to BYC. I've cleaned out our inherited 11' x 9' chicken coop which is a barn bump out. I removed all the old hay, shavings, top layer of dirt. Under the dirt is solidified ancient poop/soil. Do I need to remove this before I add shavings, hay? I'm going to try the DLM with sweet PDZ. I'm undecided about using Food Grade DE after reading all the posts here. I do plan to use the litter in the compost. Anyone know if 40 yr old dried chicken poop will be harmful for the new flock? Thanks in advance.