Unlike acidic unblockers (which can damage metal pipes over time), HG uses (lye) and other surfactants to break down hair without generating intense heat in metal pipes.
According to the manufacturer, HG Drain and Plug Hair Unblocker works by:
Following the old instructions will lead to disappointment. Here is the based on user success.
The dual bottles work in tandem to dissolve not just the hair, but also the "glue" (soap and grease) that binds it together.
(4–5 stars)