To answer your question about how to apply the slacum, this is how I was taught by Abe Chaber.
Color the wood. Shake the slacum up mixing it well
Apply the slacum using a thin cloth like a piece of old T-shirt.
You dont have to worry about runs, dust , fingerprints etc.
Cover the entire stock.
After about 3 or 4 hours the oil will become very tacky and scummy.DO NOT allow the slacum to completely dry throughout the entire process.Sprinkle on some rotten stone over the stock. Use a clean cloth dipped in linseed oil to vigorously rub out the scummy finish. The slcacum / rottenstone slurry will remove the scummy oil, at the same time this sticky goo will be driven into the pores of the wood and fill them. The slurry also polishes the wood surface. Wipe off any excess and repeat this process until all the pores are filled and the wood looks like it should. DO NOT allow the slacum to completely dry throughout the entire proces or you will have a hard time rubbing out the finish. Keep in mind that it will take 3 to 4 hrs to reach the tacky point so pace your coats accordingly.
