Sprinkle a coating of baking soda over the couch and let sit overnight. The baking soda naturally deodorizes.
Vacuum the sofa the next day to remove the baking soda.
Fill a spray bottle with white vinegar and mist lightly over the couch. This naturally deodorizes without harming the couch.
Use a steam cleaner to remove set in stains and heavier odor. Fill the steam cleaner with water and steam cleaning solution and use the hose attachment just as you would a vacuum cleaner. This deep cleans and deodorizes the couch.