I use it on the droppings boards beneath the roosts. Just straight PDZ, no sand mixed in. Seems to work well. I scoop the boards about once a week. (I should probably do it a little more often, but it seems to be fine with four chickens.)
I too use it on a droppings tray which I scoop daily. At around $10 for a 25 pound bag, I'm not going to be putting it on the floor or mixing it with shavings any time soon. It is worth every penny though, as I've not found anything that adsorbs as well and can be safely used in the coop.