I can tell you what I do with mine... I soak it in my iodine solution for about 15 mins to allow the sanitizer to soak into the stone well. You can be sure that the stone is saturated when the iodine solution is seen working its way up the tube (if you keep the air tube on it during sanitation which is what I do). I then take it out of the solution and turn on the air to it so that it pushes all of the sanitizing solution out of the hose and air stone. Once there are no more bubbles coming from the stone, it is probably dry enough to use but I usually let it go for a bit longer till I am ready to put it in my starters or my wort. When letting it dry in this manner, make sure that its not resting on a surface but suspended by the hose so that all of the cleanser will drip off.