I have psoriasis on my scalp and use coconut oil like waterlily suggested. I leave it on overnight then before I wash it I use a fine-tooth (read nit!) comb to loosen and get rid of the flakes (I'm pretty brutal and scrape the comb along my scalp). My hair is fairly thin and only shoulder length and the psoriasis is only on the lower part of my scalp (from behind my ears and down) so it's pretty easy for me to comb them out, you'll probably have a bit of a struggle with your hair being so long.
I've used different oils and found coconut the best by far, it washes out really easily with a low-poo.
3b in South Australia.
Last edited by Starmie; 12-13-2012 at 12:05 AM.