I found this recipe in "The Complete Book of Essential Oils and Aromatherapy" by Valerie Ann Worwood.
It is called a protein gel, and is used like pack or mask

1/2 oz. plain gelatin
1 cup mineral water
1 teaspoon cider vinegar
3 drops carrot oil
3 drops clary-sage

Mix gelatin & h2o until you have a smooth liquid.  Stir and leave it until if forms a gel type substance, but don't leave it to set.  Add the vinegar, carrot & clary-sage-this will prevent it from becoming solid.  use as a hair pack, covering the whole of the hair.  Leave on for 10 minutes, then rinse off throughly.  Use once a week.

I've never used this, but it sounds OK to me...