I recently read 6 rules of engagement for talking to conspiracy theorists, where I found this nugget of wisdom:
Never question someone’s intelligence or moral sense, as this is the quickest way to end a conversation
This may help explain why most conspiracy-debunking fails - you can’t have a conversation with people you’ve dismissed as stupid, or worse, evil, which is what happens, for example, with the Educate Yourself injunction, or using the Dunning-Kruger effect as a weapon to demean those who hold an opposing viewpoint.
All that that approach is likely to achieve is to push them away towards the welcoming arms of those who benefit from the conspiracy theories. Maybe this could be a way to connect with them? (with the pre-requisite of letting go of our notions of superiority: by having the humility to accept that we may also have unwittingly fallen prey to a conspiracy, or at least a flawed world-view?)
They [conspiracy theory believers] sometimes see themselves as healthy sceptics and self-taught researchers into complex issues. Avoid criticising or mocking this. Instead, present it as something that, in principle, you value and share. Your aim, after all, is not to make them less curious or sceptical, but to change what they are curious about, or sceptical of.