Something many people fail to consider when talking about so-called "swearing" is in many idiosyncratic dialects across the English-speaking world, such words are used liberally in the unstressed case, where the actual meaning and intent is anything but vulgar. Most of the time, these words simply fill out the rhythm and cadence of a sentence, lending emphasis to the words that precede or follow. You might think that the overuse of these words in a casual manner would reduce the impact, and on the page, that is probably true, but in real life... No. The stressed case of swearwords works exactly the same in these dialects as in more "refined" (cough, cough, white middle-class, ahem, excuse me) versions, and such speakers use the stressed case no more or no less than other people do--and for the same reasons.
Having had a fairly unusual life journey so far, I happen to pretty fluent in at least two such profanity-integrated dialects. I would be VERY hesitant however to write such dialogue in a book in completely naturalistic fashion. My sense is that it would be very distracting on the page, hard to read, and liable to alienate all but the most understanding readers. If I were to portray such a character in a novel, I would add only as much of this "color" as I thought I could get away with--to give the realistic flavor, without actually being fully naturalistic. Honestly, the same could be said about any idiosyncratic dialect. Important to get it right, but easy to over-do.
On the other hand, if I was writing for the screen, I might be more inclined to go for something closer to full effect. What people are able to understand aurally with the full human context of delivery can greatly exceed what they can process through written language alone.