Hi there! Hanging feeders seem to really help with the pooping in the food and water, for the exact reason you mentioned....they move. I hang them at beak level for them, so they can get their beaks in there to drink or eat. Hanging it at just the right level also prevents them from scratching in the feed and throwing it all over the floor.
Another way to keep poo out of the food or water, is to put the feeder or waterer up on a crate or something, just high enough so they don't have to bend over to eat or drink......
Also, I use those rubber buckets for waterers because they're just the right height for adult chickens to sip out of, and a bonus is, that in the winter if they freeze, you just pop the ice right out of them.
Hope this helps you,
Sharon