I was watching a guy slaughter chickens on Youtube yesterday. He cut the head off, plucked it and then debilled it. Then tossed it into a bin of other debilled chicken heads.
This was supposed to be taking place in Guanajato, Mexico, but nowhere in Mexico have I ever seen the chicken head cooked. Still, it is possible someone uses the head. How, I cannot imagine.
Look for it on youtube. It was posted by mexicandude5. I would post a link, but I forgot how to do it.
Rufus