I've tried the Brownell's Whiting on MANY M1 Garand and M1903 gun stocks that were saturated with oil or grease. Some times it worked and sometimes not.
I'm going to look for the stuff Dan mentioned and try it.
What I use when nothing else works to get oil or grease out of gun stocks is "Purple Power" Cleaner Degreaser you can find at Walmart and normally in the Auto Section. However, it contains LYE and you absolutely must use chemical resistant gloves, some kind of eye or face shield and use it outdoors. I also have a bucket of water around in case I get it any on my skin to quickly wash it off. I use White Distilled Vinegar to neutralize it and then wash that off with plain warm water. THEN wipe the stock dry with paper towels and get it INSIDE out of the sun where it can SLOWLY dry out so cracks don't form in the wood from drying too quickly.
Gus