Moisture. How do you get it? There is really only one way and that is by adding water to your hair. Now, most type 4 textures can’t just wet their hair and retain moisture that way, we have to seal that moisture in through the application of an oil based product.
However, if your deep conditioner*’s first ingredient is anything but water, you are never going to get the moisture your hair needs from the use of that product.
The first ingredient in any product is what it is mostly comprised of, so any product that you use for conditioning purposes must have that as its first ingredient. Anything else is just marketing. This applies to DIY deep conditioning treatments as well.
If you are creating a deep conditioner from scratch, make sure that water is the primary ingredient in your formulation, and utilize a binder like xanthan gum or guar gum to thicken it so that it will stay in your hair. This is also perfect if you want to utilize your deep conditioner for the purpose of curl training.
In order to retain water inside the hair shaft, a sealant like oil must also be a part of your deep conditioning* treatment. Effective deep conditioning products usually contain shea butter*, coconut oil* and/or olive oil.
For DIY deep conditioning*, I highly recommend olive oil and coconut oil* as sealants in your product mixtures. Other high conditioning ingredients for DIY mixtures include: honey, avocado, coconut milk, goat milk, molasses, and there are more I’m sure some of you DIYers have stumbled across in your experiments.
My deep conditioning recipe might not work for you due to a variety of reasons depending on the state of your hair, but I will say that any deep conditioner* should have the following basic ingredients for maximum efficacy (listed from highest to lowest percentage within the product/formulation):
Water as the primary ingredient
Complementary conditioning ingredients
An oil to seal in moisture
As long as you have all three of these, in this order, in your conditioning treatments, your dry, under-conditioned hair will respond favorably.