Of course the Ouija has never even produced a word, much less an accurate answer. This is when I introduce the idea of eliminating variables and invite them to set up their own experiments at home doing just that. I realize that I am not a scientist and that this experiment has holes in it big enough for James Randi to levitate through. But with this age group, it seems to work very well. As we discuss other paranormal subjects, I ask the students to think of ways they might test the claims.
Many good answers surface, and discussion on how to eliminate variables gets lively.
When we finish this section, I ask the students to make posters to illustrate the phrase Extraordinary claims require extraordinary proof. The poster voted the best is placed in a prominent spot on the wall for the rest of the year. But some do become skeptical about some of the topics. And at least the seed has been planted in others, and we can only hope for future germination. Obviously I am biased and really like this approach.