I have 11 chickens with a 12'x24' run and 8'x4' coop. I keep shavings in the coop and nothing but the ground outside (mostly dirt with bark, rocks, etc). I do a "mini-clean" of the coop every day that mainly includes keeping the nesting boxes clean. I remove any poopy/wet shavings and replace with fresh shavings. Once every other week, I do a slightly more labored cleaning - my girls tend to "mess up" 2 parts of the coop more than anywhere else, so I shovel out these parts completely, add some fresh shavings, and mix it all together. 4-5 times per year, I clean out all of the shavings and replace with complete new shavings.