Just remember! The longer your mixture sits in the alcohol the more chlorophyll and plant matter that will be in your oil. Personally, I do it for no more than 30 seconds of swirling, the t-shirt Idea is great! You defiantly don't want white stems coming out, think of what your smoking!! If you do it right, your liquid should have a nice golden tint to it, might look like piss. You can leave it to evaporate or double boil, or just put on something warm. Remember, Iso IS flammable and if your stupid your going to kill yourself.