Clean it first, have found mineral spirits and cheese cloth or the gray scotch brite pads work well for this.  Apply the MS and rub GENTLY on a small area and wipe off with paper towels.  Dirt and grime are not additives to any finish I know of. Once satisfied it is clean, or as clean as it will get, apply a 3/1 mix of BLO and MS liberally and rub in for 5-10 minutes and wipe off excess. After a day or two apply again but only enough to wet the stock and rub with your bare hand until it feels warm.  Wipe off the excess and repeat daily until you are satisfied with the finish. This will reproduce the shiny finish you see on some stocks, but gloss will depend on how smooth the stock was to start with.  If the stock is extremely dry you can start with a 2/1 mix of BLO/MS which will penetrate better.