I might have a solution to your problem: Use heavy sewing thread wrapped around the plug about 1/3 of the way down on the plug. Use enough wraps to build up to a tight fit and pull the ends of the therad under using the same method as wrapping a fishing rod guide. Cut of the ends of the thread short and secure with a drop of Crazy glue. If you still need a tighter fit repeat the process. I use this method for securing the leather covered plugs for leather covered recoil pads and it works very well.
Just a thot!
