I guess I would have to ask what the foundation of your coop flooring is before I join the argument. Do you have a dirt floor, wood floor, Plastic, or possibly cement? I started with a nature provided earth floor. A lot of natural sand mixed in with the dirt. We layered it with straw after some reading up on the deep litter method used for winter situations. Trust that when I say the poop and amonia smell built up awful and it all mixed into the soil and sand over time. Come spring, it was a heck of a mess and cleanup to remove about 3 inches of pure disgusting muck had to be removed. Sure, sand and dirt is absorbent. Ask yourself what it is absorbing. Over time, it too has to be tended to. A wood floor or cement in my opinion is most likely the best. Easy to line with straw or pine chips and easier to maintain and dispose of. A bale of either spreads quite a long way inside a small coop and is very comfy and cozy for your chickens. Keep it clean and keep it simple!
I didn't have a problem with smell. My coop is 6x8, dirt floor, and I housed over a dozen birds over the winter, none of which would go out because of the snow. I started DLM early october with dropped leaves/yard rakings and when those ran out I switched to hay. Coop got a light cleaning in february because the pile under the roosts was so high that when trying to add to it everything just rolled down. Proper cleaning, back down to bare earth, didn't happen until late april/early may. Also, the vent was covered over from november until late april, but I do open at least one large door during the day, both if the wind isn't too bad.