Using someone's good reputation or visibility to promote harmful ideas in order to push people to agree with them.
The "Trojan Horse" is a tactic of whitewashing / blackwashing in which the target to whitewash/blackwash are not simply chosen from what's already available, but are "created" specifically for that purpose.
First, a certain character from among the elites is chosen on the basis of their ability to appeal to the masses. It could be for his/her charisma (a political leader), his/her academic credibility (a professor), his/her good looks (an actor) or his/her innocence (a little girl).
Second, the selected character is instructed to do or say things that everyone would recognize as good or true without in any way compromising the status quo; the substance of his speeches must be simplistic and obvious enough that even a kid could understand them and agree with them, while their form must be polished enough to make it sound like some deep philosophical truth.
Third, the selected character is given an enormous visibility; he will start being promoted by major media outlets, giving speech before vast audiences, making appearances on tv shows, writing books or articles for newspapers and so on, until everyone will know him and hail him as some sort of hero and/or genius.
Finally, once reached widespread popularity, he will be trained to promote dangerous and anti-liberal ideas so that people will easily accept them just for having been promoted by their guru, or instead to attack other good (but actually useful and potentially revolutionary) ideas so that people will reject them for the same reason.
Using someone's bad reputation and visibility to promote good ideas in order to prevent people from agreeing with them.
First, a certain character from among the elites is chosen on the basis of how bad an impression he evokes. It could be someone particularly ugly (or maybe even good-looking, but that gives off some sort of "villain" or "madman" air about him), or with a very distinct lack of charisma.
Second, the selected character is instructed to intentionally damage his own image as much as possible by doing or saying things that are either openly nasty or openly stupid (or, in alternative, things that are not inherently wrong, but that still go directly against commonly accepted knowledge or morality, and are therefore guaranteed to be frowned upon by the masses).
Third, the selected character is given a high (though negative) visibility; all major media outlets will talk about him, condemning him for his unacceptable views or deeds (and he will be instructed to go entirely along with this), further cementing his position as a "bad person" in the eyes of the masses.
Finally, once reached widespread unpopularity, he will be trained to say some actually good or truthful things, and/or to attack the status quo's lies and projects; because of his bad reputation, people will automatically assume the opposite of what he's saying, and therefore stray even further away from their own interests and towards the elite's ones.