I use Sweet PDZ, granular. Haven't gotten a bag in a while though. In my chick brooder, I would lay down newspaper, followed by a sprinkling of Sweet PDZ, then topped with shavings. Newspaper was to make cleanup easier, but as they get larger they shred it while scratching anyways. Really helped keep the smell down. Need another bag because my cats stink, works great in the litter box (mixed w/ regular cat litter).
I think you mentioned trying kitty litter in the coop. I wouldn't, as some of the litters have additives for absorption and odor control that I suspect would be harmful if ingested by a pecking chicken.
So True ...who knows what they put in cat litter ...probably not regulated in anyway
Info on PDZ