Exposure to the oils found in poison oak usually causes an itchy, uncomfortable rash. Exposure to the rash itself is not toxic unless the oil is still present. Never burn poison oak because the oils emitted into the air can cause serious problems. If poison oak oils get on your clothes, launder them in the cold water cycle two or three times. If the oil has gotten on an another object, such as your couch, clean the area to remove the oils. During the cleaning process, wear protective clothing, including gloves that you can easily launder or dispose of afterward.
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.