I've done it a couple of different ways when desperate and still used oil. Double boiler, very low heat in a toaster oven (line a small baking sheet with parchment paper but make a dam, because the oil will get runny, put oil on paper and heat at about 225 degrees for 20 minutes or so)how would you decarb cart oil, just give it a heat treatment as is, or do you need chem equipment to do it?