So you had me doubt myself, especially when the first thing I found when searching for the episode was the STDWYTK episode on him, but it looks like I'm half right. Turns out Parsons was the co-lead of one of the LRH episodes, which is the one I was thinking of: How L. Ron Hubbard Made An Antichrist Using Sex Magic

Robert is joined by DJ Danl Goodman to discuss Jack Parsons and Black Magic Scientology.