If people know at least that there is something wrong with their listing than maybe they'll got the idea.
There ISN'T anything wrong with a site suggestion that we can't fix. There never was, and there never will be.
And honest amateurs or businessmen won't suggest more than one or two sites anyway, there's no point in training someone to do something they'll only do once or twice in their life. You let them take their best shot, and then (if it's worth doing right) you fix it.
So who's suggesting more than one or two sites? Only two kinds of people:
(1) Spammers--people who don't follow the rules we've already given them. And we want them to stay as ignorant and inefficient as possible.
(2) Professional website designers or website promoters. And ... they can perfectly well learn whatever they need, at their own expense: it's professional training, and they can pay each other for it. There is no reason, no reason at all, for the ODP amateur volunteers to provide free vocational training to professionals. And it wouldn't be fair to anyone to try.
See, the problem you are trying to solve just isn't real. There is nobody helping the directory who NEEDS the training you're describing and can't get it from their professional peers.