I recently found an extremely interesting medical film of a dog vomiting in an x-ray. There is nothing "gross" about it since it is just an x-ray. But it is fascinating to watch the vomit-to-be suddenly get moved back from the small intestine into the stomach. (If you've studied my FAQ, you know this is called the retrograde giant contraction.) Then you see the material move as the dog retches and then ... up it goes. Then the whole process is repeated.
I recommend this clip for emets because instead of vomiting being terrifying and disgusting, we see the process that lets the dog (and us) live instead of dying from the poison.
http://www.youtube.com/watch?v=f6y5SykbqJE