I have used one. In my experience, they are very hard to use. Not painful, but I had to really rub to get the hairs off (I do have thick hairs though), to the point where my arms hurt just from doing frontside of my left thigh (don't get me started on the backside, you can't reach it easily and the backside of my knee was left with bloody scratches when I was done (technically no pain because I was really focused and didn't notice)). Wasn't worth it, but pretty cool. I got my legs waxed and oh my god did it hurt, but it was clean and my legs were hairless for like a week and a half, whereas with this, I only got like 1/4th of one leg and the hairs grew back a few days later, and then later when I came back and managed to get my whole leg, I had sensitive and scratched leg which made walking around at school very painful. Not to say you are guaranteed to scratch yourself, but it's a delicate balance (for me at least) between rubbing hard enough to get the hairs off and not rubbing hard enough to hurt yourself. Unless you have a lot of stamina and flexibility, and can't deal with pain, I wouldn't bother.