I think the trick to odor control is what you take out and how often, not so much what you put in.
In other words, a little poop smells a bit, a lot of poop smells a lot.
The suggestion of kitty litter may help as it removes moisture. I haven't tried it but I have noticed dry poop has less aroma than wet poop.
i wouldn't use cedar chips (toxic to chickens). kitty litter would not be good because they might eat it. unless you find some organic all natural litter. most people use pine shavings and some use DE with the shavings.
A well ventilated coop will stay dry (well ok unless you live in Seattle, in which case, not always <g>) and unsmelly. So I'd say that is the primary solution.
I like wood shavings the best, the kind you buy in big compressed $4-5 bales at the feed store. Other options exist too, of course.
I am a big fan of having a droppings board (just a plain board, you can vinyl-cover the top if you want) that you scrape off every morning and remove the poo from the coop. That will remove at least half of the day's poo supply *right there*, in about ten seconds. Just use a dustpan or wide scraper, and snowplow along the board with a bucket moving along with it to catch the poo.
Simple pine shavings work really well. Don't over-crowd your chickens.
When needed, add more clean shavings on top or clean it out, depending on whether you want to do the deep litter method. Either way works.
A smelly coop might have a ventilation problem or a water leak. Most of the time, there is just too much chicken poop for the amount of shavings. Like a compost pile that has too many wet, high nitrogen green components and not enough dry, brown, high carbon components.
I use pine shavings in two coops and Aspen in the banty coop. I pop in every morning and evening with a cat litter scoop, whisk broom and bucket to police things up. Takes two minutes, lets me monitor my girls' health, keeps down the smell to near nothing, makes the shavings last longer, keeps coccidiosis at a minimum, keeps me humble and out of trouble (mostly). Time well spent.
We use wood shavings too- from a feed store. We have about four inches deep of them. It does get smelly but once you rake the droppings to the bottom then it smells nice again.
My brother has a chicken wire floor in his coop (he doesn't need to walk in it because he can get to everything from the outside). Then the droppings fall to the ground and his coop is high enough that he can reach underneath and shovel out the pooh when it gets thick. He loves this design, however, it does get to be problematic when it's really cold outside- because it's hard to insulate. We have pretty cold winters in Kansas though and his chickens come out of it just fine!