'This cake is very moist. This is the moistest cake I've ever eaten. You could smear, splurt and squirt a dollop of juicy things on top. I hope it doesn't congeal though.'
Jarring words yes, but again, it's the connotation. They reek of sex (moist, splurge, squirt) or dirtiness (smear, congeal) the phonics in themselves are inoffensive.
Speaking of splurge and squirt, now these are onomatopoeic Derxa. Cunt as you rightly inform us isn't, however, are you suggesting that onomatopoeic words are always pleasing to the ear? If not, what was your aim in using the term? I'm not following your thinking (especially as here are two rather grotty examples).
As for my own use of cunt. I use it simply because it is the worst word. I use it for it's ability to shock. If it were to be replaced by another worse word, then I'd use that instead. I would not use the N or P word because they don't mean "awful person", they are specific and racist terms. Cunt, as clearly shown already on this thread has two meanings.
If I was sexting, then I'd use cunt in it's second meaning, albeit also as a shock tactic. If the new worst word was relating to male genitalia, I'd use that too, for exactly the same reasons. This doesn't make me a misandrist, indeed I believe myself to be every bit equal to a man, and so too the reverse stands.