Re: Romex Clip?
I suspect that canuk is right. The clamp is to secure the cord so that it can't be pulled or yanked loose within the disposal. They are easy to install, however the metal screw in type as shown will require that the pigtail be disconnected from the disposal to install the clamp, the reconnect the wires. An easier clamp would be a plastic insert type which fits around the wire and is then inserted into the hole. I couldn't find an image to post here to show you, however they're very similar to a grommet, but have ears within it to prevent the cable from being pulled. There are several different styles of the plastic type and you'll find them in the electrical aisle with the rest of the electrical hardware.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!