<human>:  What's the best way to clean a stained leather couch?
<bot>: The best way to clean a stained leather couch is to create a cleaning solution of equal parts white vinegar and warm water. Dip a soft cloth in the solution and gently dab the stained area, taking care not to rub too hard as this can damage the leather. Once the stain has been removed, use a dry cloth to wipe away the solution and let it air dry.