Is it possible that he is one of the "uncredited" musicians on Bowie's "Baal" EP? Baal, in 17th Century goetic occult writings, is one of the seven princes of Hell. The name is drawn from the Canaanite deity Baal, who is mentioned in the Bible as the primary god of the Phoenicians.
Bowie was very interested in the occult back in the day. He once bought a home that belonged to Aleister Crowley, and reminisced in an interview in the 1990's that it was the Manson murders that first caused him to be fascinated with the occult.
Why doesn't anyone ever bring this up? Possibly because Bowie has money and power, and his mainstream image is no longer compatible with the occult, which has become woefully out of fashion compared to its heyday in the sixties and seventies.