They are adorable! I agree about the food and water.... and saves a heck of a mess, no doubt!
I am using the same pool right now in the house as a chicken keep.... originally used it for an injured hen (and a buddy, so she wasn't lonely) then for Gracie and her brood of 6 for almost 3 weeks (they are back into the coop now) and now it is again being used for a hen with a cut on her back, and another buddy hen for her.
We put down a heavy sheet on the floor, then the pool and then surround it will 3ft fence panels we bought used (I think they were rabbit hutch fencing originally).
DH and I are planning on picking up another one, maybe a bit bigger for future use once they are back in the stores again.