Densa, they do work well, but usually in a larger abbatoir as opposed to a farm kill.
We would electrocute the pigs, stick em to bleed them out, then into a very large and very hot tank of water they went for a short time.
Then they were flipped up into a dehairing machine - effectively a large amount of stiff rubber paddles with metal ends that would turn the hog but take most of the hair off. We would apply basically a flamethrower/torch to burn any excess hair off.
After leaving the dehairing machine, that particular tool would be used to yank the toenails off and the inside of that tools mouth would be used to scrape any hair left on - usually by the feet.
The more you know