I've used Oil-Dry before, packing the ball in a bucket of Oil-Dry and then leaving it out in the hot sun during a summer afternoon. I had better luck when I heated the Oil-Dry than just using it at room temperature. Of course, the improvement was only temporary.
Lately, I've become a firm believer in Doc's Elixer. It is much easier to keep the oil out of the ball in the first place than it is to extract the oil out at a later date. I'm currently using a Trauma Response that has well over 500 games on it, and it is still going strong. I occasionally rescuff the coverstock, reapply the Elixer after any rescuffing and about every 25-30 games, and keep on truckin' with it. The Elixer has given me better results than anything else, but of course you have to do some periodic coverstock maintenance on the ball too.