So, how do you henna your hair?

 Deb washed out the henna, and shampooed.  Her hair was thick and silky after the henna, and was deep auburn rather than dark brown.  The gray stained golden red.  The henna didn't cover the gray in the first round, but if she continues to henna, the gray will gradually take up more and more henna, blend in with her auburn hennaed hair.   The more you times you henna your hair, the more the color will build up.

Henna keeps your hair silky, thick, and healthy.