Some of my best writing professors told me to use words sparingly and make sure every word counts.
They said unless dialogue either develops character or forwards plot, it is an unnecessary waste of words.
They also said that good dialogue is not necessarily 'realistic,' but is 'real,' meaning it reveals the important issues of the story, without including the repeated 'Uh's' and 'hmmms' and 'swear words' that can bore the reader with repetition.

I was also taught to write to express, not to impress. Forget your audience and express what is in your heart. If swear words are in your heart then express them.

I was also taught that a writer must write in his or her own voice. So I would say that if swearing is your voice, write it.

Strong language in some novels, and in some plays and movies, consume the action and stop communication. In other novels and movies, they are an integral part of the story. Almost always if used repeatedly, they become boring and I stop reading or watching.

Just my thoughts.
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