we use wood chips. works just fine. I rake it pit once in a while and put old stuff around my trees and new stuff goes it. Do it every several month. Mine free range, so do not do it very often as they like to run about...
I actually emptied my brooder into my compost pile for the first time the other day just before it rained. So I have an idea of what it will smell like. There was a slight smell, a combination of woodiness and ammonia. Not horrible. I turned it with a rake and it was fine. I am definitely going to go with grass clippings and yard debris combined with wood chips for the run.
Thanks!