I had this issue with an HW35 stock, so much linseed oil that the smell was making me feel physically sick and it was actually greasy to the touch.
Initially I used industrial strength paint stripper and a loads of plastic scourers to remove the residue. I followed this with 'Cillit Bang' kitchen degreaser and loads of elbow grease. I eventually removed virtually all the oil and was able to refinish how I prefer with water based colour followed by at least 12 coats of laquer.