Hmmm, now there is an interesting point, and now quietly I'm feeling a little worried. Looks like I better check up on my local laws before I plan on doing any more! It never occured to me that some ways might be illegal in certain countries (Australia).
I had a friend offer to use this method on the 7 roosters I had, and I spoke with a vet about it and she was a little concerned that if the animal was not pulled from the shoulder region, chances were there would be several other dislocations (legs, lower spine . . . ) before the neck...