An emollient is rubbed into the skin to soothe and moisten it, while a soap substitute is simply used to keep it clean.

BBC: NEWS | Health | Warning over child eczema cream

Several children who found aqueous cream irritating when applied as an emollient reported no problems when it was used as a soap substitute.

BBC: NEWS | Health | Warning over child eczema cream

An excellent substitute for your TSA-confiscated toothpaste is soap and salt.

FORBES: What I Learned In Boston