Naturally Repair Wood With Vinegar and Canola Oil for super cheap. Use cup of oil, add cup vinegar, white or apple cider vinegar, mix it in a jar and then rub it into the wood. You don’t need to wipe it off; the wood just soaks it in.
How to restore scratched and worn wood. for watermarks - mix a thick paste of olive oil and salt and rub onto the wood - leave it for about 30 minutes. The salt draws out the moisture and the oil feeds the wood, Then rub Old English Furniture polish