Just ask the right questions. Doesn't matter where. Could be when you go to church. Or at a barbecue. Or even standing in the grocery line. "Do you think its makes someone evil to criticize another country?" "Do you believe it is wrong to disagree with some people?" "Are people who genuinely criticize others just hateful or can criticism be useful sometimes?" "is it wrong to point out problems with one group just because something bad happened to them in the past?" "Do you think experts are always right?" "Can even experts and professionals get it wrong sometimes?" "Can whole groups of people who claim something is true, get something right?" "Is it safe to rely on things 'probably being true' just because a lot of people claim they are?" Along those lines. Because these questions are completely harmless, and make people commit to their answer. Congratulations, you'll have primed them to reject arguments from authority, "muh racism!" and "muh antisemitism".