Joe,
You better watch what info you give out. After the Holidays one of the big boy manufacturers is liable to patent the methods and sound and be selling the shafts for $300.00 a piece.
Sure, like Eddie's 747 jump cue had phenolic ferrule tip back in the mid 80's then someone else patented it.
Phenolic threaded plugs ( 1/2 20 tpi ) are sold by Unique now.
I use a threaded plug even harder than phenolic. You can't tap it.
I call it Zylarta b/c my mentor Zylr invented it.