Is there truth to what he says? I know people who really are slobs and don't mind admitting that they are, and I know some who are in complete denial. At there ho use, we have to literally step over junk, and yet they say they are not slobs. Usually someone doesn't say something like that unless there is some truth to it.
But, that being said, he seems to be going tremendously overboard. Telling friends, telling parents? That's just odd. Usually someone will tell their friends and parents if their ex was cheating, if she was a *****, stuff like that. For all my slob friends, I can honestly say that none of us ever talked about that behind the person's back. Of all the potentially bad traits for someone to have, that's not even in the top 10.
I'd look at it this way. If the worst that your ex could say about you was that you were a slob, you must not have that many bad traits.