How do I remove the reviews and recent events from Movies?

How do I wipe the comments from the movies page? I was playing around with adding movies and commenting about them. I deleted what I had worked on and then tried again. Then I deleted the movies but the comments are left- all of them! I want them to go away- a clean slate, nothing there, all gone. I know how to delete the movie but I can't make the comments go away. I don't need 27 reviews of Hot Fuzz that say the same thing!