Sabotage of a Vessel

This story replaces Season 5 onwards. What if there was a way for Sam to Sabotage his body such that no Angel (or fallen Angel) would be able to use it as a Vessel? What would Sam have to do? And what role will Dean find himself playing in this task? This story has a very original plot not ever seen before! Yes again, really! Contains Wincest! Slash!