it's called RamOut-i used it once on the second floor of my house and had all the windows open and an exhaust fan on and it stank the place up beyond belief(however it did a great job on the drain problem)-i think it's non-USP grade sulfuric aacid
Most places use a low PH chemical agent now to eat through clogs especially in health care facilities where fumes can be an issue. Really though if you wanna get the job done fast just use a 5 gallon shop vac instead. No joke it works better and quicker than any plumbers friend and most chemicals.