One of the big problems for teachers is that there is not much written about this in in easily accessible literature. Also, there is little agreement on the terminology - medio(-)passive? middle voice? ergative verbs?
I tended to treat this as lexis as much as grammar. When such verbs came up, I would point out the way in which they could be used both transitively and (with a similar meaning to the transitive passive) intransitively. I did not think the use of any of the terms I put in bold above helpful - but that was just a personal opinion.
I disagree with your colleagues who feel that it is too uncommon to be dealt with in class. It's common enough for students to know about. That's just an opinion, too.
- For Teachers