Your toilet is made of porcelain. While porcelain is tough, it has terrible thermal shock resistance. Pouring boiling water (212°F) into a cold toilet creates sudden expansion. This causes the porcelain to crack violently—sometimes instantly, sometimes an hour later.
A cracked toilet bowl means water leaking into your floor joists and a full toilet replacement. A $200 plumber visit is cheaper than new subflooring. If you want to try the hot water method, use hot tap water only. Your water heater is set to roughly 120-140°F—warm enough to melt soap, not hot enough to shatter your throne. hot water for toilet clog
The best tool is still a flange plunger (the one with the extra lip that folds out). Use hot water in combination with the plunger—pour the hot water in, then plunge. The heat softens the clog while the suction breaks it apart. Your toilet is made of porcelain
