There's a trick used in restoring milsurp rifles (keeping in mind that one has to be very careful when deciding to alter a stock on a milsurp gun) but that is to use Easy Off oven cleaner. It will remove finish, oil, stain, etc. You end up with a fairly light stock after the treatment.
This trick wouldn't work well on any sort of checkered stock, however, since the whole thing needs sanded afterwards and the checkering would be trashed.
Actually I did do the easyoff stripping of the stock, then a light sanding. It looked pretty good bare but when I put the finish on it there were a lot of patchy light and dark areas. I have done this before several times and the results have been good, but this particular stock came out looking lousy
You can take the oven cleaner method a step further by actually using bleach afterward .Bleach will not only lighten the color but can also be used to open the grain on some very dense wood so that it will take stain. I knew an old gunsmith that used a lye concoction to bleach out the stocks.