I'm mostly onboard here, but there's some nuance to consider.
Wipe all expression from your face, and stare at them. [...] Bystanders will literally stop what they’re doing and watch.
Fact. Monkey see, monkey do. If you physically pass as someone older and wiser, this works even better.
Their brains will scream “I’m about to be excluded from the group”, and they’ll start babbling. They’ll confess their sins and be harsher on themselves than anything you could say
Plausible, but I think this outcome is one of many possible. Pressing on an individual's psychological weak-spots can trigger a fight/flight/freeze/fawn reflex; your anecdotes are centered on the "fawn" response. I would caution the reader that, unless you know that person well, you really can't predict which of the four you will get in this situation. If doing this you MUST be prepared for that fight reflex to kick in; they may get mouthy and/or physical. Social justice is important, but do take your opponent's height, weight, build, and if they are armed into account, before proceeding.