I'd just add on that there's not much academic research on it because nobody's going to give that funding due to politics, but there's anecdotal reports that the pornography is quite destructive.
The basic idea is that the porn hypnotises you into becoming a sissy bimbo woman. Occasionally there's a coercive fantasy element as well, e.g. the speaker is a man's wife, who is forcing him to sissify himself and serve her bigger, more masculine lovers, or a chad is surreptitiously subjected to sissy hypno and loses all his muscles and becomes a cross dressing whore (and specifically is turned on by how he has become a cross dressing whore).
It's an extreme form of a humiliation fetish, based on the idea that being a woman is the most humiliating thing you can be, and it's a self-reinforcing one. You see threads of sissy hypno in the postings of a lot of the AGPs on here ("Uwuu I'm such an anime slut, big men are going to plug my amhole tee hee~~"). Guys who got into it and then got out of it talk about having extreme impulses to transition, or beginning to develop a deep seated misogynistic world view that women are all brainless whores. More than a couple of trans women have written about "discovering" they were trans as a direct consequence of the pornography. It's also why AGPs (who are ostensibly straight men) may end up having sex with men, because the idea of being penetrated by a man is validating their fantasy of becoming a sissy submissive (they're turned on by the idea of themselves as women or women-like, hence the autogynophile).
The pornography probably isn't actually hypnotising the men, but part of the eroticism is the idea that by listening to it they are permanently changing their brains.