Advocado would work well as the oils can penetrate the hair shaft and actually make hair stronger. Coconut oil and olive oil can as well. See the thread on "coconut and olive oil" - there is an article on this very subject.
For the past month, I have been putting 2 tblspoon coconut oil on my dry hair prior to shampooing. I think that my hair is looking healthier and not as poufy or frizzy, especially with this crazy heat and humidity setting in.
I started a thread called "pure creamed coconut" that describes what I did.
Hope this info helps.