Many people have made a similar, honest mistake: After spotting olive or vegetable oil stains on a tablecloth after a dinner party, they toss the covering in the washing machine – only to discover that the stain has clung to the fabric. So while you might be perturbed to find a similar stain on your microfiber sofa, consider it a good thing that you can't toss your sofa in the washing machine. Try one of two removal methods, the second of which might be more effective on greasy or clingy oils, such as medicated scalp oil or stains from oily hair in general.
Use a Solvent
Blot up the oil with a clean cloth. Be careful not to spread the stain or imbed it into the sofa fibers.
Sprinkle baking soda or cornstarch on the remnants of the stain to help absorb it. Let it settle there for about 20 minutes. Remove the baking soda or cornstarch with a vacuum attachment.
Test a dry-cleaning solvent, which you can find in the laundry aisle of large grocery stores, on an inconspicuous area of the sofa. Squirt some solvent on a rag and dab it on the upholstery. A "green" solvent -- or one that is labeled "environmentally safe" -- might allay any of your concerns if you have never used this product before.
Blot at the oil stain with a clean cloth. Work from the outer edges to the interior edges of the stain until the solvent is fully absorbed. Repeat until the stain disappears from the sofa.
Use a Detergent
Saturate the oil stain with a pretreatment stain remover. Follow the directions on the product and give the remover the proper amount of time to penetrate the stain.
Apply a little heavy-duty liquid laundry detergent, full strength, directly onto the stain with a soft sponge. Rub the stain with hot water, using as little water as you can to work in the detergent without soaking the couch. Repeat this treatment, as necessary, until the stain is gone.
Dry the couch with clean cloths or a blow dryer. Rub the microfiber with a clean cloth to restore the puffiness to the fibers.