What is the difference between saying “gosh” and “God”, as well as substitutes for profanity? Sure they are different words, but we still give them the same meaning. So is it better to find reasons not to use “darn”, “heck”, etc?
In examining this question, usually the matter boils down to a simple principle, that of emotional mastery, or self-control. After all, one who has mastery of their emotions would have no need of using any of these words.
However, God knows we aren’t all that good at emotional control, and that’s why the Atonement is there. No matter how hard we try, there’s going to be some trial that pushes just the wrong buttons, and we’re going to want to vebalize our frustrations. In those situations, which would we be better off using, the softer terms, or the generally accepted full-on vulgarities? For my part, when those moments arise, I like to just utter nonsense syllables, such as Yosemite Sam of cartoon fame. It’s less offensive than even the soft terms, and sometimes it gets a laugh from those around me.
In the end, the reason we use any words like these is to express our frustration, which is a normal experience in this life for everyone. If you say the softer terms, but really mean the harder ones, then maybe some prayer is in order. If you’re just fed up with a bad spot you’re in and you lack any other words to use, then I think it’s fine. It’s all in the intent of the action, and only you can determine what that is for yourself.