I really cannot stand  claims that things 'nourish' the skin and hair when applied topically. What evidence exists that the particular substance actually penetrates the stratum corneum to affect living cells? Hair is dead. The visible skin is dead. Only certain substances can penetrate to the living cells and vascular supply.
http://www.ncbi.nlm.nih.gov/pubmed/16685150 Which commercial chemicals can do this? How about that nice acne medication based on Vitamin A structure? Is sodium lauryl sulphate really harmful?http://www.ncbi.nlm.nih.gov/pubmed/8033548
So, if there are herbal substances that do this, which ones are they?

I make all natural commercial chemical free soap. I will not claim that it 'nourishes' the skin, because I do not know that any of the plants or spices that I put into it can effectively penetrate the layer of the stratum corneum and make it to the dermal layer. I can say truthfully that pure saponified vegetable oils featuring all natural ingredients for color or odor do seem to be kinder to the stratum corneum than commercial chemical detergents and thus do not weaken that barrier significantly. Soap is easy and fun to make. Anyone can do it, if reasonable safety measures are taken.
Here is a nice description of skin structure and function: http://www.healthyoncare.com/skin-structure-and-function/.html