This reminded me of one time Derek Acorah did a show in Belfast a few years back. I didn't witness it sadly, but my brother was there and apparently it was glorious.
The audience spent the entire night just fucking with him, stringing him along saying yes to all this info he was giving them about their relative as if everything he was saying about them was spot on. And then after a few mintutes the audience member he was talkiing to would interrupt and say, "Oh wait I just remembered, I don't have a relative with that name/that relative is still alive actually." Things like that. All night. I wish I'd been there.