I think what you're thinking about are the Cyco polyamide tensioner friction insert replacement, here:
I've read that some guys have tried them, but haven't seen any reports of their longevity yet. Too new, only been available for a few months. Theoretically (based on the tech specs of the PA46 nylon) they should be slicker, last longer. But so far, the empirical evidence is a bit thin. I just replaced mine with OEM, or I would try them. Always up for hitch hiking home.