The club face cleaner, (as described by the Wenger tool list), or groove cleaner is a tool exclusive to the Wenger golfing models.
It is a folding pointed spike mounted on the bottom of the knife, where the reamer would normally be located. It is used to clean dirt from the grooves found on the face of golf clubs. It could also be used to clean dirt from golf shoe cleats, or as a golf tee punch.