I am using it right now! I bought Quikcrete builders grade (I think?) - not the playground stuff, cause I was being cheap. Anyway, it works great. I took the paper towels off when my chicks were one and two weeks old (I have two groups in the brooder), and at first they pecked at it like crazy, and I was kind of worried. I finally decided that they'd be ok, since in nature they don't just eat dirt until they die, and they were. They pretty much leave it alone now (they are three and four weeks old)
I found that my kitty litter scoop didn't pick up the tiny little chicken poo, so I actually use a dollar store colander - just scoop the dirty sand into the colander with a plastic coop, shake the colander, and out comes nice clean sand. It takes me a little less than 10 minutes/day to get it all clean (my brooder is 3.5 x 2.5 feet sq).
I really like that I can get all the poop out, and have pretty fresh bedding everyday without any additional cost.