Well, I just did this and thought it was hilarious.
Since everybody does Coren Direbrew over and over with the same group after you kill him, as soon as you kill him, queue for a random heroic and most people will accept thinking it's for Coren Direbrew again. And if they end up staying well have fun , if they leave, then you'll be put at the front of the queue for a tank, using the system just like having a tank queue for you then leaving, it's all the same concept.