This only works in specific circumstances. It is better used online to shame bad-faith actors who are here to poison the well.

I'm telling you emphatically from experience that II really don't think this is the case for the vast majority of people in real life most of the time. If you have gotten to a point where they say something shameful, then it can be good to put a foot down and call it out as the bullshit it is, but there's a few effective ways to do it and many ineffective ways to do it.