strap wrench trick?

Can anyone shed some light on how to use a strap wrench? Is there a trick?

I bought a cheapy from HD, and couldn't get it to grip. Then I went back and bought the expensive one (20 bucks) thinking it was a quality problem, and it still doesn't grip. So now I think it's an operator problem. Am I just an idiot?

thanks-
ed

strap

No, it is a lack of instruction thing. Go to a sporting goods store and get some pitcher's rosin. Put that on the wrench's strap and it should work properly.

Thanks, hj. I'll try it out.
-ed