ArkansasAnon here. I grew up an hour from Blanchard, heres some stuff about it that might not be public.
The tourist part is well paved and developed. You can tour a lot, but there are other parts accessible. If you go there, there's a whole section off the main tour that opens to caverns you need "gear" to get in. It's a paid tour…but what better way to have an area for dark shit, and have tourists literally cover your tracks? The Cabalists could easily use those parts of the cave for rituals, clean up, and then open it the next day for a guided tour and no one would know who had been back there.