I used to suffer from what I thought was dandruff - turns out I wasn't rinsing properly at all, I was leaving soap in my hair.
Thats all I can suggest, rinse really well or try a rinse aid - I guess vinegar or lemon mixed with water.
Believe it or not I heard on the radio from a hair professional that people don't leave shampoo in long enough to do the job. He said to leave it on for a minute or more so it can work. I tried it and the same day I noticed my scalp didn't itch as much. Now I do that almost every time (if I remember) and wallah! no more flakes. My hair is shiny too. I use the 99 cent stuff. I'm a believer.
I suds up my hair then suds up my body. I rinse my hair then rinse my body. Then I put conditioner in and while the conditioner is in my hair I rinse my body. Then rinse the conditioner out.
Tea tree oil is a natural anti dandruff substance . You can buy shampoos with it in there or buy the tea tree oil and mix it with your own shampoo in a 5 percent concentration aka 1 ounce of tea tree oil for every 20 ounces of shampoo.
This tip was given to me by a cosmetologist friend for the hubby and it worked.
I have had persistent dandruff since "forever." Turns out it's a reaction to fragrances and citrus ingredients. I started using a hair gel that contains a little bit of citrus (orange oil) and I figured it was okay since my hands weren't reacting to it. Nope. Dandruff came back. I found a similar product that is fragrance and citrus free but I was planning to use up what I had before ordering anything new.
Baking soda worked great to exfoliate and remove the flakes. Discontinuing the hair gel kept dandruff from restarting.
Sharing because dandruff isn't always a microorganism problem! Might be as easy as switching or discontinuing hair products.
I have eczema issues. When it flares up it gets thick and flakey. I get it in my ears and in my hair in some spots. I grease my head down at night with that thick lotion I make. It washes out easily with shampoo. Carmex also helps, but is hard to get out.