Source: https://kathysteinemann.com/Musings/cursing/
To swear or not to swear ...that is often a dilemma for writers. Will you lose your die-hard readers if your characters swear? They may be a cursing personality type, but many readers don't like to read - and thus have in their mind - hard-core swearing.
Kathy Steinemann explains how you can prevent your readers being intimidated by profanity and thus appeal to a larger reading audience if you avoid cursing.
In saying that, she also accepts that zero profanity is often unrealistic. If you overdo the cursing, your work will come off like the amusing tirade of an angry adolescent. Eliminate all but the occasional necessary swear words and follow Kathy's examples of how to change your sentences to show that the character may be cursing, but not in actual swear words.
In her article, Kathy gives a truly comprehensive list of ways a write can show cursing but not actually using F-words or worse. To see what I mean browse down her long list of alternatives to swear words and then see how you can do similar with your characters that swear.