How does lowering water’s surface tension help wash a soiled surface?

Lowering the surface tension of water is a critical first step in the cleaning process because it increases the liquid's ability to spread and wet surfaces.12

Surface tension refers to the affinity water molecules have for each other, which naturally resists spreading over a surface. By reducing this tension, detergents and other surface-active agents allow the wash liquor to more effectively penetrate the structure of materials, such as the fibers of a textile. This improved wetting capability ensures that the cleaning solution can reach the interface between the water and the soil, facilitating the subsequent displacement and dispersion of dirt and grease.1