das, i only just saw this thread. Members who have not seen this thread, may not know to ignore.
I agree with the strategy outlined. Correct me if i am mistaken, but this is what i've heard called on other boards as a Troll. Basically, you get rid of a troll by boring them to death.

When they are bored, they move on.
Not all, certainly, but many trolls are adolescents.... that's right... kids. We know this because troll activity increases after school hours and during school vacation times. Hard to believe sometimes by what they type... but it's true. I think it important people realize this possibility. No response is best, but sometimes people have been tempted into responding in ways that are not appropriate responses to children.
In addition to ignoring, other boards i've been on have given moderators instruction on how to better identify trolls, and the power to remove posts written by abusive or racist individuals, and advertizers. Quick response in removing inappropriate posts soon after they appear prevents the good members of the board from accidentally responding, before they realize what they are dealing with.