What decision did those that were already aware of it make, in order to optimise this activity?

Acknowledge the other person - their intent, the effort they've made, and/or the things they've got right. Be sincere rather than superior. E.g. to an anti-vaccine conspiracy theorist, I might say "I understand why you're suspicious of big pharma, and I know that you're concerned for the health of children. However, I believe vaccines do far more good than harm, and here's why..."

This helps take heat out of the exchange, by making it clear (on an emotional as well as intellectual level) that you aren't attacking them. If they don't feel themselves and their status under attack, and you demonstrate an interest in understanding them, people can feel more secure and be more open to understanding what you're saying.

It's not infallible of course, and it's not enough on its own. Follow some of the other good suggestions on this page, as well.

E.g. if you're making an effort and the other person is still on the attack, disengaging is wise. My preference is to briefly say why I'm disengaging, wish the other person well, quit, and stop following the thread (unsubscribe, unfollow depending on the platform)..