We fought the dog on the living room couch battle for about a year then gave up. We have disciplined the dog pretty well otherwise, he's very obident, but this was a loser.
He knew it was wrong, and he knew how to avoid getting directly caught most of the time (you could hear the plop as he jumped off the couch as your walked toward the room). In the end it was a battle we decided to not spend the time and energy on fighting. Less stress for all involved, and since we allow him on other couches it was also probably a bit confusing for him.
It helps that he doesn't shed at all, and is usually very clean and the couch is dark colored. And, generally, we like having him close to us when we are relaxing. A small price to pay for what he gives back in return.
Charon