I think the disconnect here is that washing your hair usually doesn’t lead to health problems the way washing a vagina does (douching even with water causes pelvic inflammatory disease, for example). It is your choice, I just wanted to provide information about vaginal health because this mentality sounds like it comes from shame rather than any health reason. It’s not nasty (again, shame), vaginas do have smells like when you’re on your period. Mine only smelled weird with one partner, and even then I’ve never had a smell for very long unless there was an actual infection going on. Smells are usually no big deal, assuming there isn’t an infection. I know you mentioned it smelling “rank” before, I think you might benefit from visiting a gynecologist. Again, no shame, vaginas are a normal part of life for some of the population.

https://www.healthline.com/health/healthy-sex/my-discharge-smells-like-my-boyfriend