I've read the same, but supercritical CO2 was definitely an alternative to hexane (or methylene chloride aka dichloromethane, in which caffeine is extraordinari

I've read the same, but supercritical CO2 was definitely an alternative to hexane (or methylene chloride aka dichloromethane, in which caffeine is extraordinarily soluble). So maybe we're both wrong, but you're not completely misremembering - that was definitely a story that was out there.