Have you tried the no-poo experiment? There are lots of reasons to give up shampoo; it's full of icky chemicals and it is expensive when compared to alternatives.
I've tried going no-poo more than once but gave up when my head turned into a grease-ball. My hair is very fine and very oily. I have washed it every day since I was a teenager. I'm told the scalp adjusts to less washing by producing less oil. yeah, uh-huh. I'd get about two weeks into no-poo before giving up.
Since I have a month between semesters I thought I'd give it another try. I did some preparation, too. I filled a half-gallon jar with sprigs of thyme and poured in apple cider vinegar. Then left it for 6 weeks so the good stuff in the herbs could get together with the good stuff in the vinegar. I strained it into another jar and waited for the semester to be over.
I stopped using shampoo on the 12th of December. It only took three days for my head to get disgusting. But I'm an Aggie so I have LOTS of hats. On the 6th day I washed with baking soda and vinegar. Obviously, I didn't do it right. My hair felt really weird and I had baking soda in my ears.
A couple of days later I washed it again with baking soda and my herb vinegar. It felt better. But still a little strange.
I waited a week. Major greasy-head. This time my hair felt cleaner on the first wash and it didn't get so oily afterwards.
This morning I repeated the routine. My hair feels thicker and doesn't lie so flat on my head. It is definitely more shiny. I think it may be a little redder, too. I have another week or so before school starts, more time for my scalp to adjust if need be.
Here's what I learned:
It does take time for the scalp to change how much oil it produces.
Infusing herbs in the ACV makes a big difference, less drying, more shine.
It is very important to brush the hair throughout the day. Using a commercial shampoo strips the oils and conditioners make the ends look good. My hair now relies on it's own oils to condition the ends and the only way to get the oils down there is to brush.
I hope I can keep this up. Fortunately, no one expects an Ag student to be fashionable so I can get away with hats every day of the week. Hopefully it won't come to that. I'll keep you posted.