Suppose that I was able to come up with an extremely compelling argument for the claim "Mint Chip is the most delicious flavor of ice cream." This argument was so compelling that regardless of what ice cream flavor one initially preferred, after reading the argument they would inevitably find that mint chip did in fact taste much better than other competing flavors.

Would it be ethically wrong of me to post this argument in text form on a forum? Or stand on the street corner yelling it into a megaphone at unsuspecting pedestrians? If the argument is truly a rigorous one such that peoples change in attitude comes from instantly realizing a truth about the world, then have they been harmed by being forced to shed a false belief?  In the more likely case, suppose that the argument simply made use of all the various rhetorical strategies fallacies that humans tend to be very vulnerable too. Is it ever ethical to use such an argument on another person, with their consent or otherwise?

This might seem like a silly question, but there are a lot of branches here that seem worth pursuing - especially considering that slightly tweaking ice cream preferences ranks close to the bottom of "potentially sinister ways to modify someone else's internal utility function." On a more positive note, if our goal is to move towards a better world and work to alleviate suffering, at some point we will need to come up with effective ways of changing peoples minds. Do we currently have an ethical framework for doing so?