Follow
We wash our hands regularly, brush our teeth regularly. We know the stink of body odor is because of bacteria in the armpits, or on the feet.
Yet it's somehow controversial to tell people to wash their hair regularly.
I don't know who's marketing campaign is responsible for getting people to fear clean hair, but your scalp produces sebum daily. Dirt and debris get trapped in that sebum. Failure to wash it off results in infections.
Wash it more frequently than once a week.