I have pretty strong feelings about swearing. I don't do it, and I don't like to work with people who do it frequently. To be honest, if I interviewed you, I would hold it against you. If you were otherwise well qualified, it probably wouldn't be the deciding factor, but it would be a factor.
However, unlike the other answers, I strongly feel that interviews are a two-way street and people should be themselves in an interview. Their reaction will tell you if it's somewhere you will feel comfortable working, unless you intend to refrain completely during your entire term of employment. It might also help you get placed initially on teams more tolerant of swearing or a better fit in other areas personality-wise. Never try to be someone else during a job interview unless you're prepared to be that person during the job.
If you want to swear and still sound intelligent, remember that vulgarity is no substitute for wit. To listeners who don't enjoy swearing, it doesn't add emphasis, but detracts from it. I'm not trying to be harsh, but from our point of view, the perception is you couldn't form a cogent argument, so you interjected an adjective so generic it can be applied to nearly every kind of situation. To me at least, it's not so much offensive as it is lazy speech.
To avoid that impression, make swearing minor punctuation, not your main statement. Back it up with well-reasoned arguments, using vocabulary worthy of a college graduate. Show the interviewer you know how to communicate well, that swearing is a deliberate choice you make for emphasis, not a mindless habit you never broke from junior high, or something you do because you can't think of a more precise word.