I know this is gonna sound weird but I've always just used plain vinegar in my steam cleaner and it works great (and less expensive) I just put it where the cleaner would go. I would test and make sure it's not gonna discolor your carpet. I use it on an off white and it's fine.
__________________ Mom to 3  's Nala, Simba and Boots  my 65 lb mutt Kovu And Kiara my precious Yorkie  |