i think this an interesting conversation, even though it has been discussed several times on this site. there are alot of home made solutions that are alot less expensive than what you can get in a pro shop.
a couple of months ago, i bought a gallon of CASTROL de-greaser in the auto section of wal-mart. i've been mixing it with roughly 50% alcohol, and it works really well. leaves the ball with a semi-tacky feel, and cleans belt marks and oil right off the ball. so for roughly $8 plus alcohol, i have 2 gallons of solution that i'd pay over $200 for at a pro shop.
just alcohol works well for me, too. i just think the addition of the de-greaser cleans into the ball's pores better and leaves a better feel.
i haven't tried the simple green stuff or 409 on my ball. i wanted to try something that was made to break down the oil. good luck and have fun!
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That which does not kill me makes me stronger . . .