I have played role-playing games since 1986, and specifically D&D since 1989. I can safely say that, in all that time, I have never tried to cast a real spell, nor sacrificed to Satan, nor been invited to join a cult, nor any of the other thousand things that D&D was slandered with in the early-to-mid-1980s.
For a fascinating expose of the Satanism myth as it is associated with D&D and other RPGs, read Michael Stackpole's brilliant research piece,
Role-Playing Games and Satanism. It soundly and proudly lays waste to the Satanic Panic that surrounded D&D in the 1980s, and continues to tint the game's popular image to this day.
For some hilarious send-ups of the old
Jack Chick Dark Dungeons tract (which was responsible for much misinformation in the 1980s), read this:
MST#King Dark Dungeons