I've delved a bit deeper into the history of the Lafayette Famulus.
According to what little documentation is available it was created by Joseph Thibodeaux sometime between 1911 and 1914. At the time he was heavily involved, if not the leader, of a fringe cult called the "Sacrifice Church" or "Church of the Blood" that practiced black magic rites fueled by blood sacrifices. Over a period of months in 1911 they engaged in multiple murders/sacrificial rites that eventually lead to the arrest of Clementine Barnabet.
This article at Real Crime Daily has a good overview of the case. I posted one newspaper account of the killings earlier. Here's another, from the April 3, 1912 edition of the San Francisco Call.
What becomes readily apparent from all of these accounts is that Barnabet and the other participants were firmly under the control of Thibodeaux. More tellingly, the murders continued after Barnabet was taken into custody and behind bars.
One particular detail I want to draw your attention to is the "hoodoo charm" being used by Barnabet and the other participants in the killings. They believed it shielded them from discovery or capture. Obviously, it failed in that regard. But what if that wasn't it's real purpose? What if Thibodeaux provided them with a charm that was part of his own, very personal ritual?
I now believe that Thibodeaux was quite honest with the members of the "Church of the Blood" when he told them blood sacrifice was the path to immortality. What he didn't tell them was that he was talking about his own life span.