I have experimented with grits and for certain tournaments that typically have very heavy oil or reverse block type appearance for me, I have gone very low.....150 grit, 120, 100, 80, 60 , 40, 24, and 12.......Although at 12 grit didn't have much success.....when I put my midnight scorcher to 12 a number of years ago--back when it had just a standard drilling on it, it would exit the out of bounds but just roll out and go straight to the 2 pin(lefty). The one big money tournament I was blessed enough to win----the 2010 U.B.A. Memorial Day Classic , I won the 10,000 first place prize money using a Brunswick dry zone solid on my first ball at 24 grit--not a typo 24 grit. Lately...at least since I discovered the 320 degree hook set drilling, I have found that I can get a similar aggressive move in the oil while being able to go a little bit higher in the grit level on any particular ball.
Brad