Regarding my color bolding above, it is my understanding that our hair is actually "dead", in that the only living cells ar at the root/follicle level, and once the shaft of hair (keratin) comes out, it is no longer living tissue. It is however in better shape towards the root than the tip of the hair shaft, especially for longer hair, as over time shampoos, styling products, curling irons and blow dryers all contribute to drying/damaging the shaft.
So by "nourish" I'm assuming you mean "improve the condition of" and not "provide sustenance to living tissue" right? Because that is exactly what silicon (+ other cons, except Neocons) do to hair. Silicon is so slick and hard to get rid of that auto paint shops do not let any product with silicon on thier premises, especially Armor All, as it gets everywhere and screws up the paint jobs it contacts.