Curb it and hope for the best, I was raised old school (the way most of our grandfathers where raised) out door johns, carrying water to the shack's I lived in and worked with men and ladies from the age of 8 years to 15 years old, yep, my two sons never let there mother and I hear them swear.... but that don't mean they don'tgotta admit - I firmly believe that you make a big deal out of swearing in front children and make it a "thing" that is a big time "no no", then they will want to swear that much more - - if, on the other hand, you don't allow it to be an issue, but also aren't running around swearing like a sailor.. they will tend to be less inclined to swear.. in the long run, we all grow up and learn the bad words - ya can't stop it, only try to curb it some..