Content Dismissal Engine

I have a forum without moderators which nevertheless badly needs moderation... I was thinking about a Content Recommendation Engine working the other way round: users could assign a negative score to topics that are turning into flame wars. Most topics (i.e. non-flame topics) would not require any user intervention at all. Users would then be able to set their "endurance level" from 1 to 10, where 10 means "display everything, even flame wars" and 1 means "apply a very conservative filtering". Apparently such a scheme originally was included in Drupal core, see http://drupal.org/node/23703 , but I can't figure out what to do with D5. Is this achievable using CRE (possibly in conjunction with other modules or special setup)? Could you suggest any other solution? Thank you.