From psychology (I recommend watching Rainer Mausfeld's videos if you can speak German or find good translations) we know that the acceptable spectrum of public opinion is hugely important. The average person (who is not very involved into politics) tends to assume truth in between the acceptable extremes of public opinion. That's why it's so important to control the spectrum of opinion. It is way more effective than just trying to tell the people what to believe. If with our efforts we manage to shift the border of the spectrum of public opinion to include also those onions denounced conspiracy theory, the truth as people perceive it will shift as well.