I have sand in two of my coops, I like it better than wood chips as long as the sand is forever deep.
I seldom have to clean those coops, the water is wicked away, and the solids just disappear...I suppose break down into the sand..
If you have sand try to feed them outside, feed droppings can screw up the sands magical properties.
We don't have sand here. On the farm we have REALLY rocky gravel but that's it.
I might just do some experimenting and see what works good. My only issue with the chips is that the birds love to scratch and pick but there is nothing for them to pick in the brooder as they waist no food during their feedings.