I strongly suspect the "hypnotist" cited as having an influence on "Freak Out!" is likely Dr. Benjamin Simon (of Boston) from this famous UFO case of the time (The Hills were Unitarians
, which made them a bit more believable, and they perhaps at the time the most notorious of Unitarians, plus they were also involved in the NAACP. Though they soon attempted to evade reporters, news and reports spread throughout the nation like wildfire. My sister, usually indifferent to anything to do with the science fiction end of paranormal, especially mentioned this case on a number of different occasions, and with new information each time, as if someone were following the case in various articles and giving her a blow by blow accounting of new facts revealed. This was 1961 that the event occurred, but the Hills did not discuss this matter with their church until March, 1963 and did not undergo hypnosis til December 1963.