Clean the couch with a carpet or upholstery cleaning machine, using cold water and the appropriate cleaning solution as instructed in the user’s manual. Go over the area with the upholstery attachment where the poison oak made contact two or three times.
Spray an upholstery or fabric cleaner recommended for the couch’s fabric onto the exposed areas then blot it away with a wet rag, rinsing it out in clean water as necessary. Repeat two or three times to remove all of the poison oak oil.
Clean the affected area on the couch with a homemade cleaning mixture made from 1 tablespoon of laundry detergent mixed with 1 quart of cold water. Gently dab the solution onto the area and blot it away with a wet rag, rinsing it out as necessary.
Wet a rag with isopropyl alcohol and blot the areas of the couch where the oils are located. Repeat several times to remove all of the poison oak oils.