In the old days (100 years ago) in certain parts of
Europe, it was not uncommon for women with very long hair to virtually never wash their hair. Instead, they would brush
talcum powder through it to remove
nasty-smelling oils and then brush a little
olive oil into it to provide sheen. They would spend several hours doing this, once a week.
In India the detergent-free soaking water from a seed (I will find the name of the seed later) was used to disolve rancid oils and the hair brushed thoroughly to remove dead skin cells.
This was not a matter of dousing one's hair with water and running one's hand through it. It was part of a carefully considered regime of personal grooming.
The key points in both of those methods, whether one agrees with them or not, is that the scalp and hair is cleansed of rancid oils to some extent, and brushing stimulates blood flow to the scalp and removes dead skin cells.
Having known a number of people who have gone for long periods of time without washing their hair with shampoo, I have noted several results:
- Unwashed hair takes on an unmistakable matted and dulled appearance.
- Unwashed hair has its own particular smell. All depending on how sharp your sense of smell is, it can be detected from a distance of several feet.
- With the absence of shampoo to remove oils and the often accompanying lack of brushing, regardless of whether your hair is long or short, a rather nasty condition can develop, known as "cradle cap". This is a slowly accumulating layer of dead skin cells glued together by rancid oil forming, literally, a scab on one's scalp. It can form so slowly and become so dense that it is not necessarily detected until it becomes quite thick, as it is so gummed with oil that it does not flake or peel.
A co-worker once complained to me that his scalp itched, and so I asked him to sit down on a stool and parted his hair to see the condition of his scalp. He had patches of cradle cap perhaps an eighth of an inch thick and was not at all aware of it. So I told him to go immediately to a drug store, buy a stiff brush and brush, not his hair, but his scalp. He did so in a back room, and when I checked on him 20 minutes later, his eyebrows, forehead and shoulders looked for all the world as though he'd been caught in a snow storm, so thick was the fall of scab and flakes of skin.
So I think there is a little more to take into consideration with this than whether or not one's hair will lay this way or that.
And after all, the scalp is an extension of one's face. Try not washing your face for a week or a month or a year if you think not washing your hair is a good idea.