If I have kids, I want to teach them they're not allowed to swear unless and until they don't need to. A swear jar with actually noticeable fees should help foster the right mind set: That the more you swear, the less valuable your swear words become. And when you can't just say fuck whenever you feel like it cause half your allowance is at stake, you're forced to develop a more nuanced and varied language to express the degree of intensity of your emotional state and whatnot. Swearing seems like an easy shortcut, but it can so easily become a crutch that limits your linguistic mobility.
Me, I've developed a bad habit of swearing on the Internet, but at least in real life conversation I've only cursed once in the last 14 or 15 years. Might have been over 20 years since my friend had heard me swear until this time a couple of months back. And you can bet your liver she noticed. I don't mean to brag when I say I blew her fucking mind hole with this one word.
And that, in my opinion, is what swearing is for. When I choose to swear I aim for effect. Goosebumps. Widened eyes. Traffic stopping all over the city and time resting like an arrow on a drawn bow. Kind of like when WWI soldiers
didn't use the word fuck in a sentence.