These do sound so badass. I want to try them at the appropriate time. Right now, with a fat gut and my small flaccid dick, I think I'd rip the fucker clean off.
Oh yeah RED, I remember trying this from PP. I should've done it last night actually, it's a pretty intense stretch! Lay it on your stomach and you're laying flat (with knees bent). However, the grip is up to you. I like to grip with my left hand right below the head and my right hand below that one. It may help to use some dishwashing gloves or something if you're having trouble getting a good grip.