Keep in mind this is for dark hair, thus the cocoa powder.
Mix the corn starch and cocoa powder then add the essential oil, stir.
The essential oil I have is from a local herbal shop.these two together cost: around $2.30. I got one ml of each (about 30 drops)
Transfer to a container that suits your needs. It could be an empty spice jar with holes in the lid or a regular jar.
I apply it with an old makeup brush