Isopropyl alcohol is fine for extraction, if you never make a mistake.
But it's mistakes that kill people.
I wouldn't dare use isopropyl, because I'm not perfect.
Quick washes with freezer cold 190 proof ethanol (everclear) won't pick up all the medicine.
To do that requires a long soak of several days to months.
Plus, many compounds in cannabis have unknown effects, and unknown dissolving times.
Here's the recipe that picks up all the medicine:
(1) Decarb the herb in an oven/toaster oven @ 240 F for 40 min using a verifying thermometer.
(2) Grind to powder.
(3) Soak for a few, hours, days, or weeks with frequent shaking at room temperature.
(4) Let settle, and strain out the nearly inert sludge, then do a second wash, and maybe a third.
(5) Evaporate/boil off enough alcohol to achieve the desired concentration.
For example, if 1 oz 15% herb went into a final volume of 1 cup, then the thc density would be (0.15)*(28,000 mg)/(237 mL) = 18 mg/mL. Many other values can be used. The tincture can added to anything or reduced completely to the tarry substance FECO (Full Extract Cannabis Oil).
Quick washers want to leave chlorophyll, plant waxes, etc behind.
We long soakers want those things, plus potential unknown stuff in our medicine.
