> However, I'm afraid that the cat is already out of the bag and many weak minds have been poisoned that wearing a mask somehow infringes rights or doesn't do anything.

Negative belief in at least the current reality of the pandemic (if not the historical reality of the disease itself), as well as in mitigation measures like masking, has become an important tribal identity marker. That's going to be difficult to counteract, and probably doesn't work on a rational level (that is, even if you could convince someone that the overt rationale was wrong, that would be more likely to prompt a shift in rationalization than a shift in belief.)