Why not just skip over and not read the comment if posted by someone you do not want to read from ?
Low tech and very simple....
Adding an ignore list feature to audiogon
Some other forums have an ignore list feature, which I think could be quite helpful and useful here. It allows each individual member to create an ignore list. This is a list of other members whose posts that individual does not wish to see. When members on the list post, it will show that they posted, but the text of their post will not be be displayed. The posts are only hidden for that member, they will show up like normal for all other members (unless they also have the poster on their ignore list)
I believe adding this feature would help reduce conflict and controversy, while still allowing everyone to post freely. It would also make the moderators' job easier. I'm not sure if the forum software audiogon uses supports this feature, but, if it does, they should definitely look into implementing it.