My friend, Perry, asked a great question awhile back. (We do things so habitually that the thought and question had never come up before then.)
The question was, "Why don't we wipe the oil off the ball AFTER EVERY TIME we throw rather than letting it soak into the ball?" That was really a great question that Perry asked.
He explained that when he threw his reactive resin bowling ball, he could visually see the oil on the surface of the ball. He then went ahead and threw his polyurethane spare ball and walked back to sit down. When he came up for his next frame, he looked at his reactive ball and there was virtually no oil on the surface - most of it had soaked in to the ball.
Our habit is to wipe off our bowling balls BEFORE we get ready to throw our strike ball, which, by then, a lot of the oil has soaked into the ball.
On a related note, my girlfriend got her Urethane bowling ball because she didn't care for the way that a reactive resin ball had so much over- and under-reaction as the night of league play progressed. By the third game, the lanes had broken down so much that she couldn't control where her ball went.
Her feeling was that if she got a ball that went straighter all the time, it would be easier to control, especially at her age and ball speed. Since she's been throwing the urethane ball, oil always shows up after every throw.
When we're bowling, nothing may show up on my reactive resin balls; but, hers always tracks oil. When others comment about how the lanes have dried up, she shows them her ball track and they can visibly see how much oil is still on the lane.
There are tons of articles written about oil soaking into bowling balls and how they will affect the reaction of the ball. Over time, the ball can lose its reactive properties and will, essentially, be a useless ball with regards to its effectiveness in cutting through lane oil and giving you the powerful reaction that you want.
There are also tons of hints, tips, and suggestions about how to wash and clean reactive resins in order to keep them in top performing condition. There are recommended periods of time and usage when it is highly important that you re-vitalize your ball and get all the oil removed from its "innards."
Incidentally, for about three weeks, I made an effort to wipe my reactive resin bowling ball after my first ball (which I always did anyway); but, I would stand at the ball return and wipe my ball AFTER MY SECOND THROW.
Well, that only caused a "traffic jam" because I was constantly in the way of the next person coming up to bowl. Which, of course, delayed our bowling progress such that we were always the last teams to finish competition.
For practical reasons, I had to stop trying to wipe my bowling balls after each throw because no one else was in the same frame of mind as me. I had to resign myself to doing the best I could to minimize the oil soaking into the ball between shots.