Does anyone have a Mister Steamy? It is a little green ball that you add water to and toss in your dryer. It is supposed to replace dryer sheets and be a more environmentally friendly product. I just received one as a gift and it says to replace it after a couple of months of use. I haven't used it yet but am wondering if it works well and how long do they last? I am also curious where do you get replacement Mister Steamys? Thanks!