I hate the word "dog whistle" because they let people sub in what they think the person said for what they actually said. I have seen otherwise intelligent people who could not even come up with a convincing straw man of what the other side believes for longstanding debates like abortion due to their bubbles.
> Some people have gotten pregnant while on birth control, therefore birth control "doesn't work". Some people wearing seat belts still die in car crashes, therefore seat belts "don't work". This is a tried and true misinformation tactic.
Now look at this from the other perspective: You have an angry person from the other side of the political spectrum insisting to them that their eyes are lying to them and that their opinions should be censored.
Would this be effective persuasion to you?
That's why I say the answer is to add context. To explain how things work and how we know things. There's a great comment on this very thread about the various mechanisms by which masks capture particles for one example.
Or with vaccines, it's not "works vs. doesn't" but that it works X% of the time in preventing infection, reduces the period for which you're infectious by Y, and decreases the chance of serious infection by Z%. We should be making the case that going from unvaccinated to vaccinated reduces your odds of something bad happening from 2% to 0.0002%.
You will note that this doesn't deny their observations, it explains them and recontextualizes them.
This is also part of how I filter opinions on topics, those who can't explain the hows and the whys do not have any useful information to offer and can be ignored.