Two things i have to ask u before i say anything:
1) Was your ball drilled by a competent driller and was it drilled
for spinning?
2) Did anyone give u ideas on how to spin or did u just test and
error?
You see, hooking the ball with 2 fingers is fine, but thing is u
are using a light weight ball, even then how many games can u hit
consistent scores.. (Hitting 10-20Pins a game also called
consistent leh!) And using a light weight ball to play hook will
result in alots of ball deflection and render your impact to the
pocket very weak. And when u up grade to a heavier ball, 14lbs...
how?
Of course, your thumb will come out clean if u get the right
driller and the proper instructions on how to throw the ball.