Trying to use Satori will not work, Guy. She hates having that ability and the only way she's able to treat regular people civilly while having it is to carefully keep their secrets, rather than using it against anyone. (Remember how she treated Renko, and her secrets?) Even for the greater good of things, she would be violently opposed to the idea of using it to mess with Rinnosuke, no matter what we do.
For that matter, Satori only really reads minds, rather than being able to manipulate them. Koishi might be able to do something, but Satori would only be able to provide a more precise understanding of his mindset, which wouldn't help very much (and certainly not enough for her to consider leaving the mansion).
We can't use her. Get over it. Pressing it will make things worse.
(Also, I expect Koishi would probably prefer to go along with Rinnosuke's scheme, since it would mean being able to trade away her mind-reading abilities, which seems to be the only thing she wants ever, consequences be damned.)
>"I might be able to pull something," - brandish a seed - "Though I dunno what it's like today."
>"What's a shrine maiden have to do for attending their shrine, usually? Just show up? Or is there some sort of ritual? Perhaps if he doesn't make a ritual exchange with someone on a regular basis..."
>"Then again, I doubt he'd be hiding away beneath his house if he had to do that more in order to fulfill this scheme..."