The Royal Flush

This is like one of those flushers that you use to get hazardous chemicals out of your eyes, but for sperm. You can shoot The Royal Flush up your vagina immediately following a condom breaking or a pull-out failure, and, with a vagina-safe and eco-friendly mixture, it would flush out and kill any lingering sperm and prevent unwanted pregnancy. Bonus if can also flush out any possible STIs. That would make life like the '70s again.