My mom had various German sayings and would use mild swear words in German when we angered her. We were never tempted to imitate that because when I was growing up it was definitely not cool to be half German!
She also picked up various American type sayings, such as "Pretty is as pretty does," "I work my fingers to the bone for you!" (Please, NO!) and "Cleanliness is next to Godliness," and "Do you think money grows on trees?!" I don't think I ever said any of those to my kids. I may have used one that my dad liked to use, "Do as I say, not as I do!" (He always said it with a sly grin.)