The Millions has an fucking interesting essay on waxing and waning influence of obscenity as a tool used both in service of, as well as against, literature.

Discussions about obscenity often devolve into this bad-faith dichotomy—the prudish schoolmarms with their red-pens painting over anything blue and the brave defenders of free speech pushing the boundaries of acceptable discourse. The former hold that there is a certain power to words that must be tamed, while the later champion the individual right to say what they want to say. When the issue is phrased in such a stark manner, it occludes a more discomforting reality—maybe words are never simply utterances, maybe words can be dangerous, maybe words can enact evil things, and maybe every person has an ultimate freedom to use those words as they see fit (notably a different claim than people should be able to use them without repercussion). Bruce’s theory of language is respectably semiotic, a contention about the arbitrary relationship between signifier and signified, whereby that chain of connection can be severed by simple repetition, as when sense flees from a word said over and over again, whether it’s “potato” or “xylophone.” But he was ultimately wrong (as is all of structural and post-structural linguistics)—language is never exactly arbitrary, it’s not really semiotic. We need theurgy to explain how words work, because in an ineffable and numinous way, words are magic. When it comes to obscenity in particular, whether the sexual or the scatological, the racial or the blasphemous, we’re considering a very specific form of that magic, and while Bruce is correct that a prohibition on slurs would render resistance to oppression all the more difficult, he’s disingenuous in not also admitting that it can provide a means of cruelty in its own right. If you couldn’t say obscenities then a certain prominent tweeter of almost inconceivable power and authority couldn’t deploy them almost hourly against whatever target he sees fit. This is not an argument for censorship, mind you, but it is a plea to be honest in our accounting.
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Like any grimoire or incantation, obscenity can be used to liberate and to oppress, to free and to enslave, to bring down those in power but also to froth a crowd into the most hideous paroxysms of fascistic violence. So often the moralistic convention holds that “punching down” is never funny, but the dark truth is that it often is. What we do with that reality is the measure of us as people, because obscenity is neither good nor bad, but all power resides within the mouth of who wields it. What we think of as profanity is a rupture within language, a dialectic undermining conventional speech, what the Greeks called an aporia that constitutes the moment that rhetoric breaks down. Obscenity is when language declares war on itself, often with good cause. Writing in Rabelais and His World, the great Russian critic Mikhail Bakhtin defined what he called the “carnivalesque,” that is the principle that structured much medieval and Renaissance performance and literature, whereby the “principle of laughter and the carnival spirit on which the grotesque is based destroys…seriousness and all pretense.” Examining the Shrovetide carnivals that inaugurated pre-Reformation Lent, Bakhtin optimistically saw something liberatory in the ribald display of upended hierarchies, where the farting, shitting, pissing, vomiting hilarity of the display rendered authority foolish. “It frees human consciousness,” Bakhtin wrote, “and imagination for new potentialities.”