Right, oil and grease are hydrophobic. This is the purpose of soap. It acts as an emulsifier, bridging the water and oil molecules together and allowing you to

Right, oil and grease are hydrophobic. This is the purpose of soap. It acts as an emulsifier, bridging the water and oil molecules together and allowing you to wash off grease and oil (often trapping dirt) off of your skin. Antibacterial soap also kills bacteria that can cause odors but most shower soap/shampoo is not antibacterial. So maybe we could get away with only using soap when we are actually dirty.