A steady stream of invective and blue language is not only
offensive and boring but also demontrates a singular lack of
linguistic imagination and edcuation.  However, an occasional
swear word does not an evil person make so let's lighten up
a little here!
  Like anything else, there needs to be a balance between
prudishness and vulgarity.  Swear when it's appropriate to do
so but not to excess.  Correct your children if they use swear
words inappropriately but not with shock and disgust.  That
makes them "forbidden" and almost guarantees the child will
use them again for effect.
  Remember - even Mr. Roger's swears - honest!  I've heard him!