Loosen drained drain
When the drain gets hard like concrete! Here is my tip!
Take boiling water, preferably with the kettle and bring to a boil. Or boil a pot of water on the stove.
Carefully pour this hot water into the clogged drain. So should the hardened, chemical powder product solve again. Repeat several times until everything is resolved.
Has worked well for me. I hope I could help!
