AHEM... Hairdresser IS in the room now..
back in the day, being the 50's-70's, when weekly shampoo-sets were in there hay day for hairdressers, some women did there own hair, when they couldn't afford or could not get in a visit to the salon. Anyway to make getting a set done was hightly appealing by women, when they had it done only 1x a week. Today, they are still some women that still have a weekly set done at the salon, but hair styles have changed since.
Norge had the right idea and I know was a marketing ploy, to have there appliances more appealing to the consumer, being a multi-functional,IE: drying your hair with clothes dryer.
It may had some women a little concerned with a dryer being Gas to dry there hair, but Im sure there was plenty of safe guards to there design( no company wants a law suit!) The methods used in the 20-40s to dry hair were FAR more hazardious than what Norge had in mind.
Rich