Here is what i do.
Whenever i choose to use Calytrade , I enable chat for that channel for the short time i am using it.
If I am selling an item I have it enabled only long enough to place ad , then it is disabled again.
All chat has the ability to block any user from being seen , so if someone is a constant annoyance to you , simply right click on their name and hit ignore.
As more people go on more and more ignore lists , they will eventually have enough people ignoring them that they will stop.
As for moderators banning , blocking or whatever punitive action taken , it is only polite and sensible as a moderator to first contact the offender and explain that action will be taken if they do not change what it is they are doing.
As for Mindarks solution , you already have it , ignore.
I personally prefer not to have Mindark take control of moderation , since they would enact a program as a nannybot , and I do not want or need a nannybot that does not like certain words , phrases or other censorship.