I used to love Lush's red Rooster soap, (I can smell it right now, just thinking of it) and also their Karma.
This year, I've bought essential oils from Eden Botanicals, and will put frankincense, myrrh, rose and patchouley -- Just one tiny drop each, in a bath.
I also was adding drops to a spray bottle, and spraying the air...
over winter. In spring summer, I like patchouley, rose and bergamot. I bought a lot of tiny vials, "samples", and they are excellent. I can feel their frequency is very good.
I can't help but feel that the dandruff/flaky scalp is related to liver congestion, and maybe also, being short of the right kind of fat.