Yes it was something of a boom for a while. I was in contact with many who grew and made oil.
All of them were untrained and unknowing and based their belief of how to do it from folklore from the 60s
Total confusion from old hippies ideas. Basically they used one of the following solvents, oil, water, alcohol. The closest one to make something goof was 98% alcohol. But that had to be frozen buds. And maximum 10 seconds process.
I quickly went ahead to Propane:)