I've been shampoo free for 5 years and yes that coincided with the moment i started shaving my head.

The skin on my had still is (and always has been) very dry meaning I would produce a lot of dandruff. 

I fixed that by using some hemp cream after a shave. I get a nice glimmer on my head and even if i shower it takes about three days before it feels completely gone and the rest of the week i will have zero skin flakes coming off.

I still use a wash cloth in the shower usually the day before shaving to exfoliate whatever might have accumulated throughout the week.

Do you still use regular soap? I only use it to wash my hands and armpits because even though i think it's quite normal to smell a bit there i really dislike it if it becomes too bad and regular water will not get rid of it enough.