If you are really determined to use it, get a rifle cleaning kit (22 or so) and push one of the wire brushes through it. I agree with the rest, for the time and money it is not worth it. It will just plug up your filters with rust scale.
When I bought mine from CJ I picked it up and was offered the extra piece. They say that it is cut off for shipping. This was about 17 years ago. It was bare metal back then.