I decarb after I make the canna butter/oil. I use coconut oil, 1lb per 2oz of bud. If you have water in your crockpot. it will not reach 220°F unless it is pressurized. Further, baking brownies does not decarb, because the brownies don't even get to 200°F. If they did, there would be no water left in them, they'd be dry and hard as a rock. After simmering for 24-36 hours, I separate the oil and water, remelt the oil in fresh water to get rid of the green taste and smell. After separating again, I heat the oil to 245° for about 20 minutes. Actually I watch the decarbing take place. Fine bubbles come out of the oil as the CO2 leaves during the decarb. Depending on the age of the pot, decarb could take 25 minutes (fresh buds) to 15 minutes, older buds. When the bubbles stop after stirring with a thermometer, it is done. 1.5 to 2 grams of finished oil is a strong dose, in the 25-30mg range.