I have a friend whose business is making hand turned bowls and other wooden art objects. He recommends walnut oil over all other oils to preserve and rejuvenate fine woods and antiques. He says stay away from any of the furniture oils that contain any petroleum distillates.
If walnut oil is good enough for antiques it is surely right for my basses. You can find walnut oil in the salad oil section in many grocery stores. It works.
Peavey USA Cirrus 5, Peavey USA Cirrus 4 Fretless, Gibson Les Paul Standard Bass, Genz Benz Streamliner 900 & Shuttle 9.0, Schroeder BMF 1215, Baritone & Tenor Sax (Yanagisawa B992 & T992)