All good questions.
Unless the cactus flesh was above pH 7, which it’s not, then mescaline must be present in a salt form like mescaline hydrochloride or something similar. The cactus flesh is acidic (around pH 5-6 or so), so the cactus must contain a salt form of mescaline, but I haven’t seen it documented anywhere which salt form it actually is.
From what I read, methanol and ethanol are great solvents to use for a crude cactus extraction. Water produces a thick slimy goo with much more mass to deal with which is almost impossible to filter. Water is not recommended. SWIM has tried all three, and methanol is the best SWIM has tried.
What I want to know is if freebase mescaline is soluble in d-limonene. It would be nice to be able to use d-limonene in an A/B extraction of mescaline. It’s much safer to use than xylene, toluene, or DCM.