Natural Leave-In Conditioner?

I've noticed lately that my hair isn't responding well to the chemicals found in most hair care products so I've decided to take the all natural approach. I've been hearing that essential oils are great but I was wondering, do I rinse after using them for my hair or can I use them as a leave-in conditioner after I wash it??? because i want to use them as an alternative to the usual petroleum-mineral oil gunk AKA pomade we WOC tend to use in our hair. Any of your thoughts or experiences would be greatly appreciated :)