Yeah, that would be a good idea, although I beleive I have at least explained him the difference between the use of positiv, neutral and negative trust or even linked our German translation of your Trust guide topic. But he still doesn't know the difference between neutral and negative trust...
If there's an opportunity, I'll provide a link to your topic of course. 


According to our DT standards, we should be hesistant to give out a negative trust for the abuse mr.relax did. Distrusting him would be more appropriate because it would remove him from DT and his left feedbacks would only be visible under "untrusted feedback". Such feedbacks would not show up as default.
Distrusting works by adding ~mr.relax to your trust list, which you'll find here: https://bitcointalk.org/index.php?action=trust
Of course, it would be the best solution if mr.relax realizes his abuse. But I doubt it after his recent abuses.
Here's also a good beginners guide about DT: LoyceV's Beginners guide to correct use of the Trust system