Darn, I never did the math. Makes sense.I'll admit, I use layer crumbles for cat litter so that could be a legitimate question from my husband. The dust from the clay kind makes me sick, and crumbles clump and control smell just as good as the alternative grain-based litters except instead of paying $30 for a 40 lb bag at a big pet store for a brand name, I'm paying $13 for 50 lbs at the local mill and can just take some from the girl's stash as needed.
It's hard to get my head around using food for cat litter, but economically, it works. I hate clay dust, too. Coats everything around the litter box.
I use Feline Pine (the Arm & Hammer substitute is terrible) because somehow it contains the ammonia odor. Makes me wonder, though, if I could find a place to buy pine sawdust cheaper.