The best shampoo I have used is Nature's Gate Herbal. I also use Aveda's Scalp Benefits for itchy days. I don't do well with the Dr. Bonners but have friends who swear by it. I really want to try the maylees homemade dread soaps, they sound great.
mix 1 tablespoon per cup or 2 of water make enough to soak your dreads
use the search feature theres gotta be like 1000 discussions of the baking soda wash as wekll as a group dedicated to fans of the baking soda wash theres even more there including variations good for wax removal