Glad I ran across this. With ten coops I've been putting a thin layer of shavings and cleaning every week. People always say diseases are carried in the poo and animals shouldn't be living in their poo but I think I will try this because the labor savings will be huge. Also the initial investment in the shavings is more but if I only clean 2 times a year I will probably end up using less. One thing to add about nesting material, I purchase the excelsior bedding pads. Sometimes I will put straw or shavings on top but the excelsior on the bottom keeps them from scratching things up so easily. If you use them make sure you get the thicker ones. I bought cheap thin ones once and ended up having to double them up and it ended up costing the same as if I had bought the thick ones to begin with. They usually last quite a while too. I only have to replace them a couple times a year.