Nothing.
No request thread is appealing to EVERYONE.
Edit: You've edited your OP from [appealing to everyone] to [appealing in general]
In my experience, you could handle this different ways. I go down the variety route. Offer a wide range of stories, viewpoints, escalations, conflicts, genres, settings, characters and partnerships. Someone might not love incest, but be into mature females. Someone might like both, someone might not be into dub-con, but really enjoy fantasy elements. Offer variation and be flexible about overviews.
The other idea is to hone in on that one thing you want. The only people reaching out to you at that point are people who want JUST THAT. Which would be awesome.
You want a zombie apocalypse and it's grim and gross and dark. Whoever responds to you, assuming they aren't cold calls, should want just that.
Just be aware that you are throwing around the word rape. That's a touchy writing request and you have to be certain of what you are asking for. Make sure you communicate clearly what you want and what your limits are.