What is it that you're trying to accomplish? I can tell you one thing, if you're looking to make a mess,.. then yeah, - you're on the right track.
All you'e going to have is a bunch of wet clumped up grass bumping out the right side of your deck. Covering the discharge chute does NOT constitute mulching. It's done evenly with seperate baffles, and even THEN conditions have to be just right for it. If you have a whole lot of grass to cut, (meaning that it is long), then you are far better off to side dicharge, let it dry, and hit it again - or windrow it and pick it up if necessary.