Ouija boards work the same way as dreaming does. In both cases, your right brain is broadcasting a message (either by text, as in the Ouija board, or in 3D moving pictures as in a dream). Neither case has any demons involved. About the only thing the Ouija board does work (and this is plenty) is in keeping those witlesses away from the door.
I have done just about everything I could to invite the demons. I got the Ouija board. I have some satanic music, and play it. I have several books that expose the Bible (it lies), yet I have no Bible or Quran in my place. I got rid of any and every piece of littera-trash I could find, and there is only a tiny chance that a stray Asleep! magazine is still floating around waiting for my shredder. And still no demon attacks--I realize that they do not attack people in the first place.