Don't do it!! You would need to go back to bare wood before applying the oil; ( Dels Ojl? ). Then you would need to apply lots of coats to soak in with possibly an end result that does not please the eye. Having gone back to bare wood why not apply a good quality varnish eg Epiphanes which will withstand the knocks and bumps and give a high gloss finish. It all depends on the finish you want I suppose and I have no doubt that the oil approach has its enthusiasts. They might be along in a minute to argue the case.