How does it work

Studies to understand how it works were performed in recent years with newer technology than were previously available. Some of these studies have proven how in effect the sperm looses its ability to stay together. When this happens, it comes apart. 'The polyelectrolytic nature of this contraceptive induces a surface charge imbalance on sperm membrane system leading to its destabilization.' - http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2818.2007.01795.x

Instead of blocking it and dealing with all the leakage issues, it allows it through after taking the sperms apart. The new plugs may include a small passage to allow some pressure relief, yet they would still require some kind of 'installation' method, nothing as simple as risug to be sure.