[CliffR]

I have drilled a golf ball.
They are under pressure. The core is pressureized by the elastomeric wrapping.
There is a core usually filled with water or oil. My state has a statute that bans the use a caustic or acidic filling. That leads me to suspect that there's a shot that older balls may have a nasty core filling.

Anyway I drilled one and it shot goo all over me.
It was gross probably just dirty old water I don't know.