Vacuum the couch with a soft brush attachment, covering all areas including the sides and back. If the couch is up against a wall, pull it out so you can reach the back. Remove the cushions if possible.
Fill a bucket with warm water. Apply a small amount of saddle soap to a wet sponge. Start cleaning at the top of the couch, and work your way down. Clean one section at a time, covering all leather areas. Wipe down the cushions last.
Refill the bucket with plain water. Rinse the soap residue from the couch using a clean wet sponge. Start from the top and work your way down. Rinse the sponge often to get rid of any soap.
Dry the couch thoroughly using a towel. Start with any cracks and crevices where water can pool. Finish by drying the front and back of the couch and the cushions.