YES , IT  WORKS !
I have had problems with the upstairs bathtub drain for years. As it is on the 2nd floor the trap is in the ceiling on the 1st floor and not accessible. Because of the location of the vent pipe you cant plunge it effectively. I had a plumber try to clear it with a rotto snake tool - but was unable to get it clear. He ended up in the garage opening the waste line and going backwards up the pipes snaking out some hair. ( Wife and two daughters all have long hair and sometimes forget to put the hair trap back )  --  Well I saw this product demonstrated on TV and bought it. - It works great - have used it twice when the water started backing up in the tub during showers.  Poured 1/3 - 1/2 bottle down drain - waited about 2 hours - put on the hot water in the tub and BAM it was clear. Drain even had that whirlpool thing going on, which it never did before.  Great Stuff.
Rating: 5 stars