From personal experience shampoos are not the best idead Shampoos are much more harsh than natural remedies like herbal rinses. Those dandruff shampoos change the way your body works, hence the Rx or drug information on the back of the bottle. Dandruff is normal, it is either skin from your scalp shedding or it is sebum (oil) created by your scalp. Shampoos change the pH of your hair and scalp, which means the pH of your scalp and hair is all out of wack. Doesn't it make make more sense to find the root of your problem: what is throwing off the pH level; than to put a temporary band-aid on the problem? Like acne and dry skin, excessive dandruff means there is an imbalance within the body or a response to the external:
Diet: dehydration, poor nutrition,dairy, salt, sugar,
Climate: dandruff worsens during winter and summer
Maintenance: massage your scalp since you don't comb/brush; moisturizing oils (coconut oil, olive oil, jojoba oil, etc) are unnecessary because the body creates its own oil (sebum) and they can cause dandruff (with olive oil: body will down regulate sebum production; unless olive oil is used very often: scalp will dry out, the body will overproduce sebum causing oily/flaky scalp); decrease amount of BS/ACV rinses, depending on water hardness even wetting hair can throw off the pH.
I will say that the best medicine/fix to our health problems is to allow our bodies' to regulate and heal itself, which it will do if the right nutrients are in the body and you keep it clear of pollutants, which includes things we eat.
This is a journey and no one thing works for everybody. Do your research and experiment to find what works for you and what doesn't work for you.
~ Peace & Love Fam