Men are a font of laundry knowledge, apparently.

Of course, Betty would never ask Joan why her husband's shirts were so dull - Joan had her eye on Henry, so that wouldn't do at all. So off she goes to the friendly neighborhood washer salesman, who suggests the proper detergent. And now Henry is saved from the clutches of Joan and Betty can brag to her about it!.

C.A. Voight was a well-known comic artist of the time.