Don’t use foul or abusive language. Let everything you say be good and helpful, so that your words will be an encouragement to those who hear them. (Ephesians 4:29 NLT)
Arguably, the language people use has become increasingly more vulgar and laced with expletives/innuendo. Some Christians excuse their "foul" talk because they say they want to be relevant to our modern culture. But, what we need to remember is that God will hold each of us accountable for the things we say (Matthew 12:36). Our words reveal what's really in our hearts (Matthew 15:18-19). If the language we use is dirty...we need to have our hearts, not our mouths "washed out."