Ah yes, this old problem. I tend to go with avoidance of the issue in my writing. I talk about the "labia" and "clit" (occasionally "clitoris" if I have used clit previously in the text a couple of times and it fits the flow of the sentence) if I need specific words. Maybe a bit over-clinical, but it suits my writing well enough.

I also dance around the issue with terms like "inside" or even "slick folds" (I swear it works in context, it just seems weird in isolation from the sentence). It really makes me wish there were more slang terms that didn't sound silly/are considered offensive.

When reading porn, I generally prefer reading the word "cunt", but I'm from Australia and our level of swear-word intensity is pretty different from some other parts of the world. I have heard this is a mortal insult in some places, where as "cunt" is occasionally used informally among friends here, depending on what circles you're running in.