> I recent came across a technique for having a more substantial discussion and it was to ask: "Well, what would it take for you to change your mind?"

Sounds like you should take a look at Street Epistemology. It is a modern version of the Socratic method that asks questions similar to that. The goal is not to make your interlocutor change their mind necessarily, but instead to explore the reasons for the beliefs they hold and whether they may be sufficently justified or not.