This is just an idea, I use a product called Neha, Herbal Mehandi (I pick it up at my local Indian grocery, $8 for a 1kg bag). Its CG friendly and is a brilliant hair conditioner and while it does colour your hair I find it much gentler on my curl then strait henna. Maybe give some thing like this a try?

Also I mix my henna with a conditioner, I still get really good colour coverage but It also leave my hair feeling healthier.
Modified CG since 8/12
Hair: BSL, Thick, Low Porosity, Dense, 3A
HG's: Moogoo, Ultraorganics Intense Camomile Conditioner and Clear Henna Hair Wax, Sukin Conditioners, CO, Spray Bottle, Henna
Low-Poo: Moogoo Shampoo
Co-Wash: Sukin Nourishing Conditioner
LI: Sukin Moisture Restoring
Colour: Henna

Last edited by Noumenon; 06-27-2013 at 10:58 PM.