I don't mean to be a party pooper,
but I use grass clippings with some leaves only, over linoleum. I have linoleum-covered poop planks under roosts and scrape daily in AM. ( Goes to garden in wintertime, compost in warmer weather.) Coop is 8 x 16 with 4 windows, 2 gable vents, and 1 turbine vent. KThis time of year until springtime, I close windows down to 1" crack every eve. No odors within a few minutes after I do the scraping and none all day long. Litter will be changed every spring. It is around 4 to 6 inches deep. Have not needed anything else to date. 24 chooks about 5 1/2 months old. Great thing is, it is free all year long. Could be that dried grass is absorbent enough to take care of any odors? Whatever the explanation, it is free and plentiful.

