It has the opposite effect! AVOID!
A friend had 3 trinkets with it equipped and we could watch his hp dwindle down to nothing in seconds right after using a med station xD.
1 grim
All grim resist, like corruption in general resist does is slow how much hp is taken over time. My current 24% corruption resist means I barely lose any health at all really from anything be it grim or damage.
What i am saying is, that his corruption rate was accelerated by his trinkets!