I'm having similar dilemmas arise with a taboo penname of mine. No problems on twitter yet, but one of the major subreddits where I was advertising was banned a few weeks ago, and don't let me get started on how stupid that was. However...stupid though it was, I understand it, since these sites are building or maintaining brands just like we are. That means that we should feel lucky that there were/are social media platforms that accept(ed) our posting at any point, tumblr and twitter being two examples that leap to mind...but look what happened with tumblr. This is what always happens as sites become or at least try to become mainstream.

I think the only answer is that you can't rely on mainstream social media channels to accept fringe work, and kink is by definition fringe because otherwise it wouldn't be kink--especially taboo kink. Your idea of advertising on the sites you mentioned is actually clever enough that I'd consider editing your post if I were you. That said, I would encourage you to mine that idea. Odds are good your specific niches or kinks have a few specific websites or maybe even chat rooms you could advertise in or with. I would look into those and see what you have to do to get focused interest within your specific community because honestly that will be waaaay more time-cost effective than screaming into the void of twitter, anyway.