Quite agree with all that's said here, I warn people about language all the time. It's not just your apparent age either, Fighter--people just don't like to be reminded of the language rule. I get backtalk, joking and challenges all the time when I mention it, but I also get a good number of people agreeing and trying to do better. That's good enough for me.

I've found that being hesitant, like "Um, guys we kinda have a rule about swearing, so maybe you can try not to do it so much?" meets with less success than being firm and polite, like a schoolteacher with a problem student. "Rasta, we have a rule against swearing in this server so that everyone can enjoy playing here. Some of us have kids, and we don't want them to hear that. Please make an effort to follow the rules of the server."

If it keeps happening, THEN you tell them they need to leave the squad, but again, make them the person who is in the wrong but being emotionally detached, and make it about them, not you.
"OK, I can see you have a hard time controlling what comes out of your mouth. I'm sorry, I'm just not seeing any effort to respect the other players here. "

"Until you can respect others, you need to play elsewhere."

"You're acting as if somehow the rules don't apply to you, and that attitude doesn't belong on a server where maturity and respect are required."

"Man, I'd really like playing with you if you were making anb effort to follow the rules--I like you, but I don't like the fact that you haven't stopped cursing. Come back when you're ready to follow the rules."

If we make it personal, that it's because they aren't listening to US, then that's when your age and voice might get in the way. When you remind them that the whole community expects this of them, then you have a lot more clout--all of TG is backing you up.

Also, making them WANT to follow the rules means not attacking them or making them feel defensive. No one wants to be seen as a jerk, everyone wants acceptance and to have friends. Use that as incentive for them to change their behavior.

Good luck, and if you ever need back-up in POE, let me know.