I have very dull and dry hair also. I made a thread about it two weeks ago when the shampoo girl at the salon told me my hair looked "super dry"
Even my mom has been telling me on a daily basis how dry it looks.
Anywhoo, I tried using some EVOO to seal in my moisturizer, as a sealer I'm not really feeling it but it did give my hair some nice shine. I just cant take the smell of it so I stopped using it and now my hair looks dry again.
I also have to be real with myself and realize that I'm not relaxed bone straight, in fact my hair is still kinky, and it will not reflect the light as well as hair that was straighter because straight hair has flat cuticles.
Another thing that I have been doing but will take a while to see results, is t
o drink H2O and eat more salmon and take flaxseed oil daily. What we do to our hair on the inside counts a lot also. Dull, dry hair can be due to a lack of omega 3's in our diet, which come from fish, nuts, and flaxseed. It will take a while to see results because a new diet will only affect the new hair coming in, and not whats on your head already.
Hair rinses can help but they dont last long on me. I did buy john freda clear glaze and I will let you know how it works.
Oh and another thing, my stylist uses jane carter's hair mousse (I dont know the exact name of it) when she rollersets but it doesnt leave your hair hard, I know we all get that nice shine after we leave the salon but I think that product really makes my hair bling, because last time she used something else and my hair didnt have that nice shine.