Jim,
My objection to the oven treatment is not so much that it doesn't work, but that you need patience and a good oven to avoid melting your ball into a shapeless blob! Hot water is just as effective and safer. According to many on ASB, a dishwasher is also effective, without the drying cycle.
As for the 'oil' coming out of the ball, go to the USPTO website <http://www.uspto.gov/patft/index.html> and look up patent no. 4,253,665 (Miller, for Columbia). Remember the yellow dot bleeders? They could ooze crap for years. According to this patent, from 5 to 25% BY WEIGHT of the coverstock can be plasticiser!
I have done the experiment with a new ball - a hair dryer on the surface of an undrilled original night hawk made it bleed.
Now, I am not suggesting that balls don't soak up oil. I have cut old yellow dot in half and seen the oil stains in the core. The new balls would be even worse, IMHO. I just don't think it comes out again - the cores are mostly polystyrene, which is the chemically most similar part to lane oil, so I think it mostly goes in and keeps going in.
The tests I ran were on a state of the art gas chromatograph/mass spectrometer system. The goop gave one peak. Lane oil gave a different peak. A mixture of both gave two peaks, one for each component. Add the fact that the ooze from the ball matched the chemical description of one of the placticiser classes mentioned in the patent, and I'm convinced that SD73's, at least, don't leak lane oil. I haven't gotten around to testing all my gear yet, but I will.
As for balls losing hit, you are right - some seem to 'die' much quicker than others. It seems a bit much to blame this on oil absorbtion, when they should all **** it up at the same rate. But what if some balls simply lose resin much faster than others? What's left is basically a urethane ball, and if its lost 10% of its filler, spongy urethane at that. Might explian why some balls hit like lamingtons after a month.
Like I said, I expected to prove it _was_ laneoil, not disprove it. I'm waiting for one of my balls to _completely_ die so I can stick it in a high vac oven and see what distills out, but I don't have one I am willing to sacrifice just yet.
Any donations gratefully accepted in the name of science, of course...
Rob.