Vivi's have a tendancy to have a lot of manufacturer gunk on them. So I generally take it all apart and wash it with some hot water, you can soak them in vodka ect but I don't see it necessary to do so. I just use pretty hot water and do a quick dry burn (burn without liquid in it and burn it so that you can see the coils down the center glow red) I do this for a minute or so and then fill it up. Vivi's also take a tank or two to completely break in and get the full flavor out of. I don't have experience with the v5's per-say but I do have a ton of vivi experience