Understand that what we're shooting for is sanitized, but not sterile. As soon as your stuff hits the air, it's getting covered in micro organisms. The idea of rinsing with municipally supplied tap water is that the stuff is chlorinated enough to be sterile in the pipe. Which is to say, go ahead and rinse with it. What you've done with your sanitizing solution is wipe out whatever little colonies of greebies are beginning to live on your equipment. Then when you brew, you add yeast which quickly takes control of the environment and eradicates the chances of survival for any other type of organism.