I wipe mine off before every shot. It bothers me to get oil on my hands, and just to see it. Of course I am a very odd person
But I agree I dont see any performance difference, BUT as for longevity cleaning the ball with some type of cleaner (i.e.-409,alchahol, etc.) will help prolong the life of the ball. After a while the ball will absorb the oil sitting on the surface, and after long enough the ball will start to lose reaction. There are ways to draw the oil out though. Hook again, rejouvanation. Actually I even gave my particle ball a warm bath, which drew out a good bit of oil. Just remember if you do this, make sure its not to hot, like how hot you would take a bath, and DO NOT! let the grips sit under the water, make sure all the holes are facing up, out of the water.
--------------------
15 years and still going strong! 15 years old that is!
DA DA DAAAAAA!! UP UP AND AWAY! TO THE BAT CAVE ROBIN!