My family owned rental property for 30 years - a 40-unit building that had its share of plumbing issues. We used this product all the time and rarely had to call a plumber. We also used it as home (my dad swore by it) with the same good results. It's hard to find but worth every penny. It's not caustic or harmful to pipes and safe enough for kids to measure out and use. One of the first "green" products out there!
This is a fantastic product - Used it for years 
