It makes damn good sense :)
I was always taught that, "salty language," was the appropriate term. A good cook knows just the right amount of salt to enhance the flavors of their food. Likewise, a good communicator knows when to sprinkle in a few off color terms for emphasis, humor, provocation or passion. Just as too much salt can render a feast inedible, too much foul language can drown out what may be otherwise valid communications.
Great analogy!