How do I keep my dog off the couch?

He's never been allowed on the couch, and he's never even attempted to go on the couch in the year we've had him.
Then last week I was washing his bed, so I guess he went on the couch to have a soft place to lay down. I shook a can of coins at him and he didn't even flinch.
Now his bed is back, and every morning, I'm finding him on the couch. There is a baby gate blocking the area where the couch is, so he has to make quite an effort to get to it. (climbing over a chair and the gate, etc).
Is there anything I can do to stop him besides start crating him again at night and when we go out? (he only does it when we're not around)

Re: How do I keep my dog off the couch?

Our dog trainer had us put balloons tied to cans of coins on the pieces of furniture that we did not want him on. That did the trick for us!

Re: How do I keep my dog off the couch?

My MIL uses aluminum foil