I'm curious about these studies. Were they looking at which way works best given a single person and infinite time, or which way works best given finite time and a large group? Was it specific to American conservatives?

Because if they don't care what words mean, then I think the better approach is to attack their social status as a group. Shine a light on what they are, make them embarrassed. Let them lose friends. "You can't reason someone out of a belief they weren't reasoned into."