Why clothes are easily washed by soap or detergent ?

Explanation

The addition of soap detergent in water reduce the angle of contact .the dirt of matter is enclosed in the clothes . The molecules of detergent are hairpin shape, with one end attracted to water and the other to molecules of grease, oil or wax (dirt), thus tending to form water -oil interfaces . the surface tension reduces drastically. Hence clothes washes easily.
Water proofing agent is added for forming large angle of contact between water and fibers.