If you ask me, the best way to turn people away from your novel through pure tags/genre is to be contradictory to the point where people think you have no idea what you are doing
For example, BL and all girls school, or putting all the different kinds of possible protaganist tags (strong protag, weak protag, lazy protag, hard-working protag, etc.) and don't have a multiple protagonist tag, and people will think you're lying.
This isn't exactly tags/genres, but if you take both sides of a controversial topic, that also works well in scaring everyone away. For example, you could have the full spectrum of LGBTQ characters in your story.... and make your story homophobic/transphobic, etc (and I don't mean having it, but supporting those views). Anyone who is supportive of the LGBTQ community will be disgusted with your homophobia/transphobia, etc , while people who are those will be turned off by the fact that you have those as the MC.
If you have traditional disliked tags like NTR and whatnot, there are a few enthusiasts for those so that would end up attracting them instead.
Alternatively, just put tags no one cares about and write something that appeals to little people on here. (like nonfiction or something)