Cover the oil spot with baby powder, cornstarch or baking soda. Let the absorbent powder set for 15 minutes to soak up the oil. Vacuum the powder from the couch.
Put one to two drops of degreasing dish detergent onto the spot. Rub it in with your fingers.
Scrub the couch gently with a soft, wet toothbrush. Rub the toothbrush over the spot using a circular motion.
Rinse the area by dabbing with a damp rag. Blot with dry rag to remove excess moisture. Repeat the process of applying dish soap, scrubbing, rinsing and blotting until the oil is gone.