A gunsmith I trust who's been in business for 40 years working on fine doubles claims the acetone only takes out the first 1/4" or so of oil. He heats the stock with some type [ won't say what type ]of acid laying in the bottom of the closet. The heat and vapors draw out all the oil. He claimed years ago he used acetone but when the job came back after a year and he's redoing it for nothing he found a different method - his current one.