What is the advantage of lathering in a mug, vs. lathering directly on your face? I figure that it has to go on there anyways. The only thing I can think of is that you can have extra lather in the mug for a second/third pass. But I've been unsuccessful getting a thick dense lather in a mug, whereas my whiskers end up helping in the lather-building process. Any other advantages of building lather in a mug? And if you build directly on your face, then what else can you use the mug for, other than holding a bit of water to work with?