Oily residues naturally resist being dissolved by soaps and other lathering cleaners, making fabric stains caused by mineral oil among the most stubborn to remove. The key to removing mineral oil stains is to destroy the molecules of the oil with an acidic solvent before trying to wash the stain away. Whether the fabric is an item of clothing or upholstered furniture, the mineral oil can usually be removed if you act as soon as you notice the stain.
Blot up as much moisture as possible from the stain with a cloth to make sure the area is not too wet.
Generously apply an absorbent substance onto the stain. Press it in gently to the stain. Let the absorbent substance (salt, baking soda, cornmeal or cornstarch) remain on the stained area for several hours---overnight, if possible.
Take a stiff brush and scrub the absorbent material in a circular pattern before brushing it away. Much, if not all, of the stain will be gone.
Pour either rubbing alcohol, white vinegar or lemon juice onto the stained area. Scrub again with the brush. Follow with a laundry pre-treatment solution. Massage the solution into the stained area and leave it alone for a moment.
Combine warm water and grease-dissolving liquid soap into a spray bottle. Shake well. Spray the mixture directly on the stained area of fabric and scrub until it lathers. Massage the lather with a clean sponge for one to three minutes. Rinse the area with warm water. Blot up excess water with a dry sponge or absorbent cloth and allow the area to dry. The mineral oil stain should be gone.