http://web.archive.org/web/20061020183334/http://www.amazon.com/exec/obidos/ASIN/0595094724/qid=984115767/sr=1-1/ref=sc_b_1/103-7655947-5136656
you have to read the comments at the bottom
I've tried constricting mine and I only got to forty and was already feeling better, laughing my a*se off, wait till I start indenting my navel
there'll be no stopping me I can't wait to shoot out a big violent blank
Now pinch........and........ release.
[Edited on 20/10/06 by Peteff]