Something a little more concentrated than 50/50 would be better in the case of Simple Green. I advocate using hot tap water (but not too hot - something around 120 degrees) which helps lower the viscosity of the oil that's in the ball's pores which helps draw out the old oil. It's not a huge difference, but certainly better than a solution at room temperature.
_________________________
Brian Longo
25+ years bowling, 8 years "behind the counter"
as a mechanic, "laneman" and in the pro shop
--"Even the expert was once a beginner"--
--"There are no magical balls, just magical bowlers"--