I’d say this scripture applies:
Jas 1:26 If any man among you seem to be religious, and bridleth not his tongue, but deceiveth his own heart, this man's religion is vain.
Modern English:
Jas 1:26 Do any of you think you are religious? If you do not control your tongue, your religion is worthless and you deceive yourself.
And probably this:
Jas 3:6 And the tongue is a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body, and setteth on fire the course of nature; and it is set on fire of hell.
Jas 3:7 For every kind of beasts, and of birds, and of serpents, and of things in the sea, is tamed, and hath been tamed of mankind:
Jas 3:8 But the tongue can no man tame; it is an unruly evil, full of deadly poison.
Jas 3:9 Therewith bless we God, even the Father; and therewith curse we men, which are made after the similitude of God.
Jas 3:10 Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.
Part of it is the definition of what is cursing. If you yell a profanity AT someone that is cursing.
You can curse at someone without using any taboo words as well.
I think THAT kind of bridling is more of what is meant, rather than considering certain terms that are simply determined to be "unrefined" being used.
However those so called vulgar words, aren't always used in a "cursing" context which is a lot of what I mean when I'm talking about the context of when I might use them. I try my best to bridle my tongue as far as actually cursing at someone whether with vulgar terms or not. It's always better for cooler heads to prevail even in a disagreement than to fly off the handle and insult or curse someone.
I think context is far more important than the vocabulary itself.
The same word in one context is not cursing but in another context it is cursing.
If I say "Praise the Lord Jesus Christ!" have I cursed? Have I said anything wrong whatsoever? Absolutely not.
But if I got angry because someone cut me off and I just said His name out of frustration or anger, then it's a curse.
If someone gets mad at someone and says "I hope a sinkhole opens up underneath you and swallows you!" they haven't said a single "dirty" word, but they have in fact, quite literally, tried to curse the other person.
That is more what I think James was on about than if they used a term for excrement in the middle of a sentence or not.
Don't CALL someone excrement, but if your toilet got backed up with excrement because the pipes froze I don't think God is angry with you about that, no matter what synonym for excrement you used.
I guess central question....
Should I correct my friends when they use Jesus Christ, or God, as a curse?