its very useful and effective if you use it right....when i clean the 3dr i never have to use a bucket or Mitt.... i rinse the car to soak with water then snowfoam leave it to dwell... then blast off and that includes the underside... then i dry with a garden leaf blower....nothing except water and chemicals have touched the paintwork... cutting the chances of swirls etc accuring.

but then again i suffer with OCD