I had Grip Puppies on my BMW F800GT - lots of vibrations in the bars. Did a good job but make the grips feel big - haha they are. First longer ride I did own the bike, my hands started tingling, realized was gripping the bars so relaxed my grip and problem solved. Put the Grip Puppies on anyway. Had them on for 26,000 miles and they lasted well. Probably were starting to approach end of life so I traded the bike but for other reasons.
EDIT: They are elastic and I with some effort just slipped them over the existing grips. Think a layer of foam rubber cushion.