Oh, I did this this morning!
My hair is very fine and very long!
I used conditioner to "wash" first, rubbing it all through, especially at the ends, left it five minutes, then shampooed, using a tiny amount, and really only shampooed at the roots, I did not shampoo the ends, just let the soapy water run down the ends of my hair, shampooed again.
I thought I might have a huge trouble getting a comb though, it is prone to getting really tangled, but it combed fine, feels lovely and soft, and it not at all flyaway or full of static.
I usually have to wash everyday too, as it gets very lank and greasy quickly, so I hope it makes a difference there! I think the longer you do it the better it is! So I am going to give it at least 2 weeks and see how my hair is then.