The chicken diapers I've seen are exactly like the design for flight suits that people have been using on pet parrots for many years. Chickens are just another species of bird. I don't use one on our parrot, because I potty trained him the first year we had him.
If I had a house chicken, I'd try potty training her. I've read that you can't potty/house train a chicken. On the other hand, I've read of a person that had a chicken that would peck at the door to be let out, when he had to go. He behaved like a house trained dog.
Chickens can tell when they have an egg on the way out and go back to the nest. I'm wondering if they couldn't also tell they have a dropping on the way out and go back to a cage, litter tray or outside for that.