I would suggest a smaller roosting bar, certainly not 4" wide. Chickens lived in trees not on flat, smooth surfaces. I have a lot of cedar trees so I've used limbs as roosts and that has worked great with Zero poop as well. If you want to buy roosts, I'd suggest looking at Carolina coops...
I've had a Carolina coop for 3 years and have never had a single poop on them. They are the perfect size and shape for avoiding it. My flat roosts however bars however, are constantly in need of cleaning. It's the size and shape that's the issue due to proximity to vent. Literally, with 100%...
My rope wrapped roosting bars from Carolina coop have zero poop after 3 years use. They are the perfect size to avoid the poop issue. The flat roosts however, are constantly getting pooped on.
I have a Carolina coop and I absolutely love the rope wrapped roosting bars. They are the perfect size and after 3 years, I still have not had to clean them off. Perfectly clean.
Goats are a high demand animal. When I inquired of my friend who owns dwarf goats and utilizes them for breeding and milk, as to which animals on her farm required the most attention and care, it was hands down the Nigerian Dwarfs. My daughter also has dwarf goats and agrees with above...