phished880 hit it right on the head. I made a Chocolate Bock, its currently bottle conditioning. It will be ready mid February. I used 3 oz of Cocoa Nibs in the secondary for 3 weeks. (3 gallon batch) It is very chocolate, dark chocolate, but mm mm good. I tasted a sample while I was bottling.
I would say if you are going to follow my lead with an oz per gallon, I would limit the secondary to 2 weeks or go 1/2 oz per gallon. But, like I always tell myself, try it what's the worst thats going to happen?