How do they get ruined? They are not that big and are not destructive like a parrot's strong beak can be. Just curious.
Ruined is the probably the wrong word, they're perfect condition for chickens, but the containers get filthy even with washing/rinsing and I just use things I would never...
I use old baking pans, old dog bowls, take out or heavy duty plastic meat containers. I try to use anything old and smooth or non-porous so it's easy to rinse out with the hose and refill... plus they're going to eventually ruin whatever you use :thumbsup