I had some k98 stocks that were totally soaked in cosmoline (dripping) and ran them through the parts washer (fresh fluid) first then stuff thats called prepsol, thats the brand name, it's thinner thats used to wipe down a car with just before you tack rag it and paint it. It drys slower than actone and pulls out more oil, after drying overnight do the acetone and finish/sand as wanted. But they were really soaked with cosmo and it cleaned them perfectly. The heat/ sunshine is a good call to get ride of all traces of thinners and oils. I'd avoid the stove/oven cleaner though, that's what I use for stripping blueing before polishing a part, don't think I'd want to chance it leaching out of a stock when reassembled and being warmed up from shooting allot, pretty caustic stuff. The boiling in water , especally on a laminated stock/guard, works but that can cause a stock to split, or delaminate. Not all laminated stocks are glued up with synthitic glues so it's a kinda last resort/chancey method. But also remember that acetone WILL attack synthetic glues, so be carefull there too. Paint prep type thinners won't attack eaither one. Just take longer to dry, a day in the sun.