My mother in law operates a small beauty shop and actually had one of these contraptions sitting in the corner, along with a wooden chair. Looks like something you'd see at the end of death row in a prison.
One time she asked me if I would take a look at it, stating "I don't think it's working right". I got a large knife out of my tool box and cut the plug off of it. Now I KNOW it's not working right...never did ask her why she thought it wasn't working right...afraid of the answer, I guess.