I used to use 190 proof Everclear as a solvent when I made Rick Simpson oil for my late wife. She suffered from pancreatic cancer.
I used a
Magical Butter machine, followed by filtering, then letting the oil sit in a tall container to let solids sink to the bottom. The less green, the better.
Once I filtered as much as I could, I generally ended up with about a Mason jar full of tincture. Now it needed to be evaporated.
I did it the easy way, by using a rice cooker. Outside, or in my case, the garage, to control both smell and fire risk. I bought a rice cooker that had a 2-hour manual cycle, and all I needed to do was to periodically add some water, and restart it every two hours. The jar of tincture went in the middle, and water boiled around it at 212F. The alcohol boils at a lower temperature, so you could watch the Everclear boiling off over a period of 6-8 hours.
Once done, I was left with a black tarry substance that was really only fluid while quite hot. At this point I mixed in 50% vegetable oil to thin the RSO so it could be handled.
I then drew up the oil into a large syringe, then used the syringe to put drops of oil into gelatin capsules, which were used as edible medicine by my late wife. I would make up capsules with different amounts of oil, label and store. My late wife would combine capsules as needed to get a proper dose, which was slightly different strength each batch. Now you can just buy the stuff, and it's completely filtered.
I was getting about 1/7th by weight in oil for the weight of buds I put into the
Magical Butter machine. And at the time (2015) the cost ended up about the same as what dispensaries charged once they began stocking it.