Removing cosmoline/oil from gun stocks.

[tombogan03884]

Since you specified "stock", I would just hang it in the sun and get some use out of the 100 degree weather.

[MikeBjerum]

The most common method I have heard from guys around here is engine degreaser and a pressure washer with the pressure turned down.  They separate the action from the stock, clean the entire gun, hang the stock outside in partial sun for a few days to dry, soak the barreled action with WD-40, then start stripping and detail cleaning the metal parts.