Texaslady,
I can't help you with the de-braining method, but I can tell you this. Once the chicken's head is cut off, regardless of what the body is doing, the chicken isn't feeling any pain. Think of the folks who have suffered spinal cord injury. Once the link between the body and the brain is severed, the brain can't feel any pain, because there is no connection to the body. Although great harm could be done to the body, the person with the spinal cord injury wouldn't actually feel any pain, because the signal isn't getting to the brain. So, while I would agree that the flapping and flying would be disturbing, if the head has been removed, what you are witnessing isn't pain and suffering, it is simply a bizarre phenomena. Don't know if this is any help.
I can't help you with the de-braining method, but I can tell you this. Once the chicken's head is cut off, regardless of what the body is doing, the chicken isn't feeling any pain. Think of the folks who have suffered spinal cord injury. Once the link between the body and the brain is severed, the brain can't feel any pain, because there is no connection to the body. Although great harm could be done to the body, the person with the spinal cord injury wouldn't actually feel any pain, because the signal isn't getting to the brain. So, while I would agree that the flapping and flying would be disturbing, if the head has been removed, what you are witnessing isn't pain and suffering, it is simply a bizarre phenomena. Don't know if this is any help.