In my research so far, I’ve only seen one time when a cultiple got ousted with a minimum of time and bloodshed, and it still took a flame war. It was the Usenet newsgroup alt.books.poppy-z-brite, and they drove off Draven (who at the time was Kurt Cobain and possibly the Crow) in April of 1999.
How did they do it? They refused to let him get his foot in the door.
When he showed a deep craving to talk to Brite, saying, “it’s sad that Poppy doesn’t know I exist. You know?” He got the response, “ “I don’t see how it’s especially tragic.” So even when he was just starting to edge into creepiness, people just went, “No, bro.” Not flaming him, but not letting him be creepy either.
The wheels really fell off the bus when he tried to groom a teenage member of the group, only to send the email to an adult member by accident. He clutched his pearls and claimed he was being flamed and attacked, but instead of getting the reaction he wanted (effusive apologies and cowed silence), the group just posted the entire email in retaliation. After all, they were already getting the tantrum, so they had nothing to lose. Kurt threw bigger and bigger tantrums, and the group just grew more and more tired of his bullshit, until they finally ran him out on a splintery rail. Sum total of time? Less than two weeks.
What’s fascinating to me is, this was the very START of Draven’s online misbehavior. Their Matrix cult was far in the future. As far as I know, they hadn’t managed anything other than creeping, and yet the newsgroup totally pegged them. They saw Kurt as a manipulative, self-pitying douchebag with a stalker complex and a thing for teenagers, and they were totally right! What’s more, they weren’t quiet about their beliefs!
Nobody rallied to Kurt’s defense except his unfortunate fiancee. (No, not Trinity, she was three fiancees later or so.) Nobody bought his bullshit. He didn’t infiltrate and take over the group like his successors would later. The harder he tried to push their boundaries and sense of reality, the harder the group clung to them. Kurt would throw bigger and bigger tantrums, until he finally just self-destructed.
I suspect that’s the only way douchebags like this can be managed, by not letting them get their foot in the door. Once they build a following, getting rid of them is damn near impossible. But without their followers, a cult leader is a sad, pitiful creature. It’s much easier to give them the boot then.
And it seems that loud conflict is an invariable part of getting rid of them. There is no way to do it quietly. It is big, it is noxious, and it is no fun for anyone, but anything less means they just keep hanging around. Anything less than "no, that is not acceptable here," and taking action will be taken as, "I will tolerate your behavior."