With a sand floor, you just rake out the poop & leave the sand. I have heard people rave about it in their runs. Don't know about in a coop, but if the floor is dirt, it sounds like a good idea to me.
Hay/straw is bad, in my opinion. When it gets wet, the bottom layer tends to stay wet & gives off ammonia fumes & grows mold fairly easily.
Pine shavings would be a better choice than straw because it dries out easier. This is what I use, then when I clean out the coop, I use it to mulch around my plants in the garden. Works great to help supress the weeds in the veggie garden & keeps the moisture in the dirt while also fertilizing.
If you use sand, don't put the poop right in your garden or you'll burn your plants. Compost the poop first before adding it to your gardens.