I posted this question on th ecarpet cleaning site a couple of days ago but haven't recieved any responses so I thought I try here.

 Hi Ann,

 I can't say from the standpoint of a carpet cleaning professional as I am not one....but I do have kids and a dog so I have it done every time my carpets are cleaned.  I always wondered if this was a gimmick but didn't like the alternative of having no protection if it does work.  :)  Sorry I couldn't help more.