Fair is fair, and I don't think the pressure should be on the ladies to prevent all pregnancies. Odds are, the majority of the time it's the GUY'S idea to stick his thing in her place anyway, so why not take a little responsibility fellas?
Well, this reads like it has good potential, but sounds a little, well, more invasive and potentially more damaging than just taking the pill:
Blockage inside the vas deferens? You ever put your thumb over the end of a hose turned on full blast? Yeah, I don't want that happening to my dick. I'll wait for more testing before I sign up, thanks.