If your drain is clogged with soap scum or animal fats, boiling water is a fantastic, chemical-free first strike.
Warning: “Your pipes are PVC + have a disposal. Pouring boiling water directly may damage rubber seals. Recommended: Run cold water during pouring + limit to 1L max.” boiling water down drain
Pouring boiling water down a drain is a common but controversial DIY maintenance technique If your drain is clogged with soap scum