You may have to take another tack and do everything in your power to teach your kids critical thinking skills. I used to do this with some adolescents in my area. I taught them the most important questions in their mental arsenal are "how do you know that ?" and "what evidence exists for that assertion?"... teach your kids to question, that it is ok to want to know the source of ideas, not to be ashamed to ask questions, and to insist on good explanations for any grand theories. You must take responsibility for vaccinating these kids against bad thinking. Cults, LGAT mindwarps, etc. grow in the absence of critical thinking skills. In that sense they are like deficiency diseases.