No matter how often you wash your hands, human skin always contains natural oils that keep our skin protected from drying out. Most of the time you don't notice this oil unless you rub your hands onto glass or a similar surface. However, constantly transferring skin oil to wooden furniture can gradually leave a stain over time. Solvent cleaners can remove the stain and restore your wood to its natural color.
Dampen a clean rag in hot, soapy water and rub in the direction of the grain of the wood to remove any oil remaining on the surface. This can also lighten the oil stain, depending on how long the stain has been on the wood.
Don a pair of rubber gloves. Soak a separate cloth in mineral spirits, a solvent cleaner. Squeeze out the cloth to remove any excess spirits; saturating the wood surface can result in further staining.
Rub the mineral spirits onto the wood, working with the grain. Allow the solvent to sit on the stain for five minutes and then wipe away any excess. Allow the cleaner to dry completely and inspect the wood. If any oil stain remains, repeat the mineral spirits application until it is gone. If the mineral spirits appear to have no effect, try the following method.
Mix 1 cup of turpentine, 1 cup of boiled linseed oil and 1/3 cup of white vinegar.
Soak a clean rag in this solution and wring it out so that it is damp but not soaked. Apply this solution to the stain using the same method as the mineral spirits, allowing it to sit for five minutes and then wiping it away.
Allow the solution to dry and inspect the surface; repeat applications as necessary until the stain is gone.