I hope I would never hit them.
I think we’d find a way to step back and continue the conversation more calmly. There’s no need for that kind of language. It’s only used to vent anger. Venting anger doesn’t really help solve problems.
I have to say that if my kids used obscene language (I guess you mean things like “fuck,” “shit,” etc), I would be pretty shocked. We don’t use those words in my family. Well, sometimes I do, but that shocks them so much that they make me calm down before continuing. So I don’t use them.
We’re not a family to get angry in a demonstrative way. We keep our anger inside, if we have much of it at all. We try to solve problems, not make people feel bad. Making people feel bad doesn’t work. Taking a constructive approach works.
So in truth, the solution to this problem starts years ago—long before you have teens. If they use this kind of language now, it means that it is something they have decided will be effective in one way or another. Maybe they want to shock you. Maybe they want you to be angry. Maybe they think there is no way they will get what they want, so the next best thing is to piss you off and make your day a hell.
To me, that kind of problem solving strategy is evidence of a much deeper problem. Somehow, these kids don’t feel like they have any power and they have no say. They don’t feel like people with rights in the family. Maybe they feel like slaves. At that point, there’s nothing to lose by swearing. Hell, maybe they can make you lose it and try to hit them. They win, in that case, because you have lost your authority when you hit them. From there on out, they never have to listen to you again. They can appease you or attempt to appease you, but you will not be getting the truth from them again. It will only be a master-slave kind of arrangement.
Also, they would probably be running away from you as much as they could. They might hide in their rooms, or hide outside the house, or be out all the time. They might turn to drugs and alcohol to dull the pain of not feeling connected to you. They might run away from home.
Hitting may gain compliance for a short period of time, and if you’re a short term future kind of person, that’s all you need. But if you are interested in the long term relationship, hitting is never helpful. It always leads to much worse problems down the road. It may gain compliance, but it loses you at least part of the kid and there’s always the danger it will lose you all of your child forever.