Maybe you can create a category called "Incoherent Posts: Please Rewrite and Post Again" and put the troll posts there. At the top of this thread, explain that you can't understand the post and the person should clarify his point for a better exchange of ideas. That's not censorship, it's helping people write English better (and believe me, plenty of Americans and ESPECIALLY Scientology-educated Americans, could use a little guidance). Since you are not deleting the posts, you can't be accused of blocking speech. And we can always go visit "Incoherent Posts" for a laugh.
On a different issue, some internet nanny programs for children may block www.xenu.net
if the site contains spelled-out f*** words. The interesting but not essential post about the origin of the f*** should either be sanitized (spelled like I am spelling it) or moved to a separate site (keep the link, though). We don't want to be blocked by net nannies at homes or school libraries (where Scientology children might log on), just for one spelled-out obscenity!