Help--oil stain on wood grip

[wdavid431]

I have a very nice Luger with light colored wood grips. However, one of them has a very ugly oil stain about one inch long. I must have over oiled the firing chamber area and it ran down into the grip.
Murphy's Oil Soap and lots of washing has had no effect. Anyone know how to get the oil stain out.
I am at a loss now, so any help will be greatly appreciated.