If I had to boil Freud down to a single proposition, it would be that some methods of self-control run so deep that a person never becomes aware of all the impulses s/he is regulating, BUT (to add a 2nd proposition) we CAN observe the impulses that are unobservable to individuals through society's symbolic matrix of prohibitions et al.
The big innovation of Edward Bernays is to provide slogans that are actually heuristics that make aspects of social reality (eg women smoking) legible to modernist instruments of social sense-making (the news).
It doesn't really matter whether public relations are influential. The advertiser creates the capacity for observers of society to perceive new categories of behavior. The advertiser sells the capacity for self-regard, via modernist media, to their clients.
By selling clients on the view that consumers were exercising self-expression, advertisers are actually selling them on the idea that metrics like sales figures are profound expressions of meaning-making from below rather than statistical noise or sectoral indicators. Advertising is meaning-making from above, for clients, but with a modicum of displacement.
Most of Bernays' stunts rely on triggering the observable mechanisms of suppression. The Freudian logic, again, suggests that society can explicitly censor that which is deeply felt but innately censored by an individual. To trigger someone, it follows, is to grab them by a handle on the inside that the individual can't even grasp. But again the trick here is in telling a story that the real meaning is that individuals are in a crisis about confronting some taboo.
I hate to be all "sometimes a cigar is just a cigar" about this, but I'd argue instead that scandal in media is just a kind of pseudo-event that helps smoothe over a problem in the distribution of those media: we don't get 22 minutes of news each evening, or 1 paper's worth, so pseudo-events help bulk up thin editions.
The advertiser needs the client to believe that the spectacle of censorship is deeply felt by the audience. The news office needs the advertiser. And so on.
There's a lot of phony arguments that are made in support of the advertiser's lore. Sure, you can point to the libidinal base for lots of personal habits. But it remains to be demonstrated that those habits are responsive to stimulus, that they're responsive to the specific media being applied, or that they're responsive in predictable ways.