They can be used for disinfection purposes especially in fabrics
Christian uses the shiny silver balls on Ana in Chapter 20 of Fifty Shades of Grey (page 362 when reading it on my tablet).
my balls
There is no specific collective noun for the noun balls, in which case a noun suitable for the situation can be used, such as a basket of balls, a rack of balls, a row of balls, etc.
balls with holes were invented in 1953 and were dubbed "Wiffle Balls."
My balls.
The sport of golf uses balls and clubs.
balls
uhh my balls?
Boules
snooker or biliards
Billiards/pool.
He now uses Columbia 300 bowling balls
Baseball, a pocket billiards game, uses 21 numbered balls following the same color scheme as the first 15, and a cue ball.
hockey it uses a puck
Golf
Making tiny carbon soccer balls?
It is probably number 1, it is what he always wanted to be, and what he is. He only uses Nike One #1 golf balls.