Better late than never, I hope? TripAtlas.com: Sorbitol is often used in modern cosmetics as a humectant and thickener. Also known as 'glucitol', is a sugar alcohol the body metabolises slowly. It is obtained by reduction of glucose changing the aldehyde group to an additional hydroxyl group hence the name ''sugar alcohol''.

Your husband is correct when he says it's a sweetener; it's often used as a sugar substitute in some diet foods, sugar-free gum, etc. It doesn't contribute to the lather in a shampoo, just supposedly attracts moisture and keeps it mixed (thickened and emulsified).

I've plugged my organic hemp oil soap & shampoo bar elsewhere, but it lathers beautifully without any strange ingredients. The oils, particularly the coconut oil, are known as contributing good lather to soaps.