Quoted from AndrewP:You are awarded bonus for each lit ball, every time you drain.
It will hold your progress each ball until you light all 15.
Lighting all 15 will light all three WOW goals for the duration of the current ball in play.
Upon draining, you will receive the bonus, about half of the pool rack will be reset (same ones every time, as evidenced in the schematic), the two WOW kickouts will reset, and the center rollover WOW will remain lit for the remainder of the game.
I know previous threads have discussed this in detail.
This is correct.