Immediately cover the oil stain with an absorbent, such as baking soda or a white paper towel. Let the absorbent sit for about five minutes and remove it or brush it away with a soft-bristled brush. Repeat the process until the absorbent no longer absorbs any oil and the absorbent comes away clean.
Hand-wash the shoe in the sink with cool water and a mild detergent. Use a soft-bristled brush, such as a toothbrush, to gently scrub the stain. Rinse the shoe and set it on a clean, dry towel to dry.
Follow the directions of a detergent-based pretreatment to apply it to the stain. Most treatments require letting the pretreatment sit, without drying, for five to 10 minutes (with reapplications to keep the pretreatment moist).
Place the shoe in a delicates (lingerie) washing machine bag. Place the bag in the wash machine with a mild detergent (read the detergent's label to determine how much to add). Set the washing machine on cold water and the most delicate cycle. Start the machine and let it complete the cycle.
Examine the shoe. If there is still visible oil, repeat Steps 2 through 4.
Set the shoe on a clean, dry towel. Crumple white paper towels and insert them into the body of the shoe to shape it and to absorb interior liquid. Check the paper towels periodically and change them if they are damp. Allow the shoe to dry completely.