Hi all--I haven't been around for a while, but I've still got my 3 hens, Clarice, Olivia and Svetlana. They have a HUGE henhouse, attached to a 10x10 chainlink dog run. See pic below (smaller house inside run has been removed). When I put the run up 5 years ago it was grass. They killed that and it became dirt. Now it's SUPER smelly, SUPER muddy mud. NASTY. I clean the henhouse but it's hard to clean DIRT. I'm just not sure how to fix this. ??? Should I put in a new substrate? If so, what? Gravel? Sand?? Something else? Is there a safe de-odorizer I can use? Thanks for any help anyone has!