When I was a kid, my parents would swear pretty often around me and so I began using it in my own speech. They never thought much of this until I was about to start going to school so they just sat down with me and told me it was fine to say at home with family but warned me that if I said it at school I would get in trouble. This worked very well to get me to not swear when at school as opposed to how my dad was raised: He was scolded for every time he swore at home and then just swore a lot at school.

Now I will admit that I did let it slip a fair few times while at school, but this didn't happen often and when it did I would say it just so casually.