Covered by…
If you have assessed the risk and decided to proceed, do not cut corners.
Mrs. Jenkins, who had been watching from a safe distance, shouted, "John, what have you done?! Get out of there, it's going to explode!" John quickly grabbed a nearby bucket and tried to scoop up some of the mess, but it was too late. The caustic soda had reacted with the pipe's materials, causing it to corrode and weaken.
Caustic soda is the "nuclear option" for a reason. It is effective, cheap, and terrifyingly strong. It saves you the cost of a plumber, but it shifts the burden of risk onto you. If the blockage is stubborn organic matter, caustic soda will win the war. Just ensure that in the process of clearing the pipes, you don't burn down the bathroom—or yourself.
Panicked, John grabbed a bottle of caustic soda (also known as sodium hydroxide) from his garage, thinking it would be the quick fix to clear the clog. He poured a generous amount down the toilet, hoping it would dissolve whatever was blocking the pipe.
NaOH reacts with organic matter (hair, paper, feces, grease) turning it into a soap-like, water-soluble substance. The reaction releases (up to ~200°F / 93°C), which can help melt grease and soften blockages. It will not dissolve plastic, metal, or mineral scale.