Hmmm he told me he used the generic plastic ones found on ebay. Non cellulose. Apparently the cellulose ones are the real deal ping pong balls to actully play the game with.
The plastic ones won't absorb water etc.
I'm still waiting to hear what all the carnage is. I think/ know my ski has taken on some water recently through the exhaust tube hole. Previous owner/builder locked it in with 5200 and the exhaust heat melted/loosened it up and created a gap for the water to enter through.