Yes you can spray vinegar onto your couch to clean and freshen the couch.
Take some undiluted white vinegar and spray the undiluted full strength white vinegar onto the couch using a spray bottle.
Hold the spray bottle at least 1 foot or so away from the couch so it does not get too saturated with the vinegar.
Vinegar is a great natural way to freshen your couch and other upholstery and you can also sprinkle some baking soda onto the couch to help freshen it and remove odors.
Then use an upholstery cleaning machine to clean the couch and remove the baking soda and other dirt and grime from the couch.
Although your couch may seem clean the upholstery cleaner will pull out grime from your couch that you cannot see.