makes me wonder if my carpet has stains on it too, where I do my neb treatments, I do them in the front room sometimes mainly in my bedroom and then the computer room at times. I would say that my bedrroom would have the most stains if I do have any, because Ill set the finished nebs on my head board and sometimes they fall off and will still have a little bit left in it, or sometimes the darn mouth piece falls off while doing the treatment and some of the med falls out, so hmmmm, Ill have to check my carpet now, cause its happened with HS, Pulmo and tobi.