I remember when I was growing up, there was a popular dry shampoo that came in an aerosol can.  It really was handy to use when there wasn’t time to shampoo hair or to use while traveling.  Now, there is a more natural, non-aerosol brand called klorane dry shampoo which might be handy for moms with young children who can’t find time to wash their hair on a busy day or a day when the kids won’t take a nap.