Right on the money Chainsaw . Brownells Whiting agent works great , when used properly !I have had good success with Brownells "Old Fashioned Whiting". You mix it with methanol, TCE, acetone or toluene and paint it on oily stock. It will turn a dirty brown as it sucks oil out of stock. Let it dry and brush it off. Repeat if necessary.
I took an old Savage 99 stock (almost 100 years old) that was severely oil soaked and was able to salvage it. It looks very good - like a good piece of wood should look like after a 100 years.
I stand to be corrected about the oven cleaner. Never tried it myself, but saw this in an old copy of The American Rifleman many years ago.Do NOT use oven cleaner. It can turn your wood black and it will go too deep to remove.