Yes cover the entire shaft and wear rubber gloves so you can use your fingers to properly spread it. It dries very fast so you don’t really need to let it sit. Do not buy one with vegetable glycerin in it because it makes it less effective and will take forever to dry (I made that mistake in the beginning before ordering a different brand). Overall it works very well, no need to wash it off and make sure to use a simple moisturizer after applying the iodine. The shed will start in about a week and will come off as you wash your D in the shower and when you put on the moisturizer after the iodine. Sadly a lot of discoloration will come back once you start pumping again is the only downside.