...Could someone explain to me the clean button?
Page 1 of this thread: http://www.e-cigarette-forum.com/forum/puresmoker/10529-bada-bings-going-supernova.html#post164307
You can push the button while it's still soaked with nicquid, and get some aftertaste, or wash it first, up to you.
If you don't let it dry fully, the first cart may vape a little crappy from all the water.