Apple Cider Vinager
Dread Maintenance
You technically don't "need" to do anything. But it is beneficial, yes. It makes your dreads nice and cuddly and soft and I feel like it clarifies the hair a bit. Maybe even balancing out the pH after you use baking soda. I tend to do it every other time I wash.
I just pour a little bit in a bowl, (I don't know exact measurements but maybe like 4 oz. and dilute it with a lot of water then pour it over my head and let it sit for a few minutes. Less time for younger dreads and more time for more mature dreads. Hope that helps!