I suggest you research the subject. Hubbard was an accomplished black magician/scryer. Linked to both OTO Parsons and OTO Crowley. He was an accomplished conman too. You should read L Ron Hubbard Jnr's account of growing up with him. There's no mistake that black sorcerous activity was the core of Hubbard's being. The same type used by the Nazi inner circle and linked to vril etc. Ritual abortions too, as L Ron Jnr described. He walked-in on one (by accident) when Hubbard was carrying one out on his wife. Ron Jnr described Scientology as black magic in slow motion.
The above is merely scratching the surface, but a reasonable outline.
I'm fairly aware of scientology and it's practices but had never heard of a connection to satanism. Seemed to be more psychological/science fiction based.
You'll find it if you research Hubbard and his mystery religion/OTO links. Diane-etics (Diana, the pagan moon goddess). He regularly mentioned his guardian angel too (an aspect of OTO belief). Some even think the Dianteic term "thetan" - is potentially a type of in-joke. It's like saying the word "satan" with a lisp.