You have to keep it dry in the coop. You mean the coop, right, not the chickens themselves? We scoop the worst nightly poop into a bucket every morning, on occasion we sprinkle diatomaceous earth (food grade!) under the roost, and that helps dry out the poop. the drier it is, the less the odor. In the run outside, you can till under some lime on occasion and that will help in the pen.
I have deep litter and haven't changed the shavings since November. When people visit, they comment that they can't believe there is absolutely no smell. My guess is that you have damp conditions. Do you need more ventilation? Maybe the run needs to be raked? I keep sand in the run which makes it a snap to rake about once a month. Hope this helps.