I use Simple Green, diluted 1:1 with water, after bowling. I adjust the cover as needed with Liquid Sandpaper (more surface) and Renew-It (less surface).
Every month or so, I usually take each ball down to 600 grit with ScotchBrite, then work it back up to the desired grit, and apply Renew-It or a polish to bring the ball to the desired level of shine.
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seadrive
Cogito ergo bowl