traveling story activities

The traveling story activity that we did in class was a lot of fun. However, I would be very scared to conduct this type of activity in a middle or high school  class where  inapporpriate topics (such as those brought up in class) should not be a part of class discussion. Inappropriate topics seemed to dominate the topics and events of the traveling stories written by college students in our course. If future teachers, at our level of maturity aren't able to keep it PG, how can I expect my students to be able to keep it appropriate? I do not forsee me trying to use this activity unless there is a way to hold students accountable for each and every entry into the story.  It was a lof of fun though!