Quick question

How do you clean the omicron v2 catrigde when puting in new oil. There is a tiny bit left over still in the tank not even a .2 but i want to clean the tank before I add my newest errl. Whats the best way of doing this. Also whats the best way to fill the tank with oil thats on some parchmench. Would it work to Just put the paper in the fill tool and heat it all up and let the oil drip down? Moving your oil after you extract and purge it is a pain lol.