SLES for dry, flaky scalp

Dear Beauty Brains and The Beauty Brains community,

My second question concerns shampoos.

I have been using shampoo with SLES since always, I think. But suddenly i got these dry scalp flakes. I was using a drugstore SLES shampoo with silicones at the time. So I switched to a SLES shampoo from Lush but without silicones. The problem persisted. Then I tried these Lush Fun bars on my hair for, well, fun. They all contain:

Cornflour, Talc, Glycerine, Sodium Laureth Sulfate, followed by essential oils, perfume and colors — depending on which color you use.

And what can I say, they’ve delivered some of the best result on my scalp and hair so far. OK, they’re not so great on my bleached ends, but point is: no flaking. Regardless of which essential oils are in it besides.

So what could it be? The cornflour and talc are clearly there just to achieve the Fun bars’ form and peculiar texture. So the only things doing anything are the glycerin and SLES, no? I’m basically washing my hair and scalp purely with detergent, and not even a mild one at that!! So, why is it still so good for my scalp and hair? Doesn’t that also mean that all that other stuff in shampoo is useless?!

Thank you in advance for your help!