As I have said before the only way to stop this is laws, let them howl about censorship and free speech, if it's factually wrong then it should not be up. Those that go to great length to produce videos should be sued. The problem is that our legal system seem to care about money than anything else. If people can sue for defamation why can't science sue for defamation?
I note that there are creators (or producers) and also the followers, so this is a bit off of the original topic of convincing followers to change there minds, but OK, I like that, but the reality is pretty complicated. You remember Sandy Hook? It was a mass murder in a US elementary school that happened 8 years ago (26 dead including 20 children).
I can't imagine a worse nightmare. A father drops his kid off at school and a few hours later has to identify his bullet-ridden body. It is crushing to think about.
But conspiracy theorists (and one very well known one) decided that it was all fake, the whole thing. That the children never died (sometimes it was claimed that some children never even existed). They have had many followers who piled on with horrific stories of how the US G made the whole thing up (to take away guns or something like that) and many of the followers directly harassed the survivors. Imagine that, after going through that trauma to have people calling you and so on, telling you that you and your dead son is all fake and how horrible you are. Tough to believe that wouldn't make your blood boil over.
There is a case in court. It is still going on as far as I can tell. There have been judgements against the big Conspiracy guy and he has even, in a fashion, said that it did happen and pleaded a kind of mental illness that caused him to doubt everything! Just last week he was reported to be outside of an election place, at a gathering, megaphone in hand....8 years later, still peddling.
You bet I would like to see these cottage industry conspiracy theorist held accountable, but the courts move slowly. If I were that father, I don't know if I would have the strength to keep going.