It depends on the person you are talking to. There are people who aren't that far down in the rabbit hole already and could still be convinced that their conspiracy-theory-/pseudoscience-stuff is wrong. I once was one of these persons. There was a time when I believed in "Free Energy"-stuff but then someone left a critical reply to one of my comments and then I started to question this stuff and rejected it completely some day. In my case debunking this stuff has helped.

Ok, there are unfortunately also many people who are already very far down in the rabbit hole and aren't ready anymore to question this stuff. But I generally think, while it isn't always possible to convince conspiracy-theory-believers I still think it's a good idea to debunk their conspiracy-theories and pseudoscientific stuff independent from doing it in a debate with the believers or doing it without directly debating them and just generally debunking this stuff without mentioning specific persons because it could help more people like me once who still aren't deeply believing into this stuff.