The Xenu story does NOT count as a straw man argument. The religious beliefs of Scientologists are just as valid and deserve just as much respect as anyone else's.
Me: "Ah, the winter solstice. This time of year is the best of all for looking out at the universe and all its beauty." Christians: "WRONG! WHO LIKES LIGHTS? LIGHTS ALL NIGHT! WOOHOOO!!!!! LIGHTS!" Me: "Well, at least those will go out after Christmas, allowing me to clearly see the stars then." Christians: "WRONG!"