When I was a teenager and helped my uncle, I was the person that held the back legs. Whoever said they were some squalling and squealing little jokers is correct. Of course if I was being de-nutted I'm sure I'd squeal too. I used to hate when he called and told me we were going to "cut some" in the morning. Never knew whether it was going to be pigs or calves until I showed up.
I remember my uncle used to spray some purple stuff on the empty sack. He said it was for the flies.