Several people have tried to do the same thing using a standard bolt and wrapping foam around it then inserting in the butt end of the shaft. I bought a used McGregor MOI putter and didnt like the grip. Didnt really like the way the putter felt for that matter. Before I sold it I decided to try a different grip on it. Removed the grip and discovered the homemade balance certified experiment. Removed that, installed a new grip and love the putter now. I just didnt care for the weight in the end. A lot of people seem to like it and think it helps a full swing stay on plane better. I dont see it, but maybe it's a good placebo for some??