can't say the same about soap use but I wash my hair very sparingly which surprises most people.
On average I'll wash it about every month with store bought shampoo that's a little fancy but I buy it at Target so it's not that fancy.
I've been doing this for many years and I noticed that my hair doesn't get greasy as fast as it used to and I'm pretty sure it's because excessive shampooing (like everyday, every other day) strips your scalps natural oils.
I do use a boar bristle brush to brush from scalp to ends which I think contributes to distributing scalp oils to my ends. Even then, the climate here is so dry that I apply a hair oil anyway.
not sure if this is relevant but I wanted to share anyway because I see some parallels.