I agree. I'm a big fan of the coarse river sand that I use. I would not be so keen on beach sand, though, as it will contain salt. The chickens definitely pick up bits of hard grit through it, so I'd suggest river sand. Here, we can buy it in bulk, delivered by truck.from New Mexico!
Oh...most definitely sand! I use it in the coops, runs, and even the nest boxes! It controls the odor to the point of no smell, it is very easy to clean, soft of the foot pads and helps prevent bumblefoot and it also contains lots of stones for those gizzards! I highly recommend it. If you have access to beach sand, river or arroyo sand, these are free for the most part. You can even go to your local sand and gravel company and they will sell it to you pretty cheaply by the truck load.
Good luck and enjoy the forums!