I've heard of liberal jews of some sect just pricking it to draw blood out by sucking on the foreskin (going off memory, was fairly repulsed).
Jews do the willy-pricking thing for male converts to Judaism who have been previously circumcised. It's a symbolic circumcision where no actual circumcision is necessary.
The sucking on the wound of a newly circumcised baby boy is a very old tradition/custom that has been rapidly going out of style -- especially now that we know that infectious diseases can be transmitted to an infant in this way. In the past, the belief was that the practice of drawing blood away from the wound prevented infection. We live and we learn. All of us live and learn -- not just Jews.
Basically I like reading Jewish history but my equipment doesn't match up. It causes alot of duress. I was actually disappointed when I took my DNA test and saw no Jewish ancestry.
Well, nobody's perfect.