I wrote a little Greasemonkey script for Obsidian Wings that will automagically disemvowel comments from users you don't want to read. In addition to good old dsmvwllng, it also has options for replacing their text with a nice white-on-black REDACTED , or to make the text really small: Look at me, I'm small!.
Updated: Now with a sweet new "I Like Pie" mode - thanks double-plus-ungood!
Update: Also, a Washington Monthly version, here.
Download / install, if you wish (you'll need FireFox and Greasemonkey, first). You'll have to do some minor editing on the script itself - to add your list of targets, and optionally, to change the comment-abusing style. But, don't worry, all the stuff you need to monkey with (ha!) is clearly commented.
Note that it only matches against the user's name, so you might just find yourself playing catch-up, if your targets frequently change their posting name (as they are completely free to do, on ObWi).
Also, this probably won't work anywhere else, since it relies on the structure of ObWi's HTML. Though maybe all TypePad blogs are similar... ?