Abbadon, your posts smack of insincerity, to say the least.
To answer your hypothetical demon communion situation, that’s just absurd. It would be sheer paranoia for every parishoner to worry, at every Mass they attend, that Satanist/Hexed hosts are being given to them. Given that you have only “heard” of this happening, it seems unlikely that it is at all, in any significant sense. People often are swayed by stories of Satanism, and it can cause hysteria, such as when there were a wave of sexual molestation arrests in 70’s because children were supposedly being molested or sacrificed during Satantic ritual. Those periods of time, however, have also provided fairly strong evidence, once they were disproven, that fear of Satanists or Satanism is largely unfounded.
Given that you also have experience with Wiccanism/Witchcraft/etc., I also have to assume that you also know, however, that Satanism is not a very significant or populated movement. Which leads me to why I believe your posts are insincere, since it would be easy to prey upon the fears of good Catholics/Christians living in fear of a largely impotent “Satanist” movement. To make a post saying you’ve “heard” that Satanists are providing hexed hosts to parishoners seems like intentional provocation.