These days, every chatshow host seems to have a gimmick for interviewing guests. Graham Norton's red chair is probably the tamest, since he doesn't actually consign the guests to their doom, but it's there. I'll mention it. James Corden, of course, not only has Carpool Karaoke for interviewing singers, he gets his film star guests to act out their entire careers.
But Anika Moa has probably the oddest approach of all. A singer and chatshow host on New Zealand's Maori Television, she gets guests to answer questions… while they're wearing a dental retainer. Here's Lucy Lawless giving it a whirl, for example.
No, I don't know if it's the same one each time or whether they sterilise it afterwards.