When I had chickens before, they were in an enclosed run and I honestly don't remember doing anything about the poo. Seems like it just worked its way into the ground or something. I only cleaned out the actual coop area which at the time, had straw in it. Right now our run is full of grass so until that's gone, we aren't doing anything because it's not easy or even possible to pick up all the poop in the tall grass and weeds. DH doesn't want to put anything down-he thinks it'll be ok just leaving it. We'll see though.