I used this in a room that I had professionally steam-cleaned less than a year ago. The waste water was black and, even though I had vacuumed thoroughly before cleaning, it still removed quite a bit of dog hair. The carpet looked great and felt very plush. Some of the odor returned after a short time so I went over it again a week later. The water was less black but quite a bit of dirt and dog hair was removed on the second cleaning.