Simple boiling water (100°C) acts thermally: it melts and loosens solidified FOGs and dissolves soap-based scum. It is most effective as preventive maintenance or after partial blockage. However, boiling water cannot remove solid debris (hair, fibrous food) and should not be used on PVC joints weakened by prior chemical exposure.
Once your sink is clear, adopt these habits to prevent a recurrence: natural sink unblocker
This is the most popular natural method. The chemical reaction creates a fizzing foam that eats away at organic buildup like grease and soap scum. Simple boiling water (100°C) acts thermally: it melts