Deep conditioning with coconut milk, honey, olive and rosemary oils has helped my hair to maintain moisture until the next wash day. Now, for some reason, I'm unable to use coconut oil as a deep conditioner, it dries my hair out something fierce. Coconut milk is another story, and it contains iron, fatty acids, and proteins to help reduce breakage and strengthen hair. So if you're having issues with thinning and breakage, coconut milk can help with this.
I like adding a tablespoon of honey (a natural humectant), 1 tablespoon of olive oil and a few drops of Rosemary essential oil to half a mason jar of coconut milk. I prefer using Thai brand of coconut milk. This can be used as a pre-poo while detangling hair. You really can't go wrong. Either way, you'll have nice, pliable soft hair. Just remember to add honey/and or oil. Coconut milk is protein and can be drying to the hair, this is why I use honey and olive oil.
Now, I don't deep condition with heat. Violet doesn't like that ( Found that out during the winter) My preferred method is steaming in the shower or with a steamer. By the end of the day even in this humidity my hair is still soft and manageable. I usually use this mixture once or twice a month. Remember, moisture and protein balance is key to the overall health of your hair.
I freeze my leftovers until I'm ready to use it again. Give it a try, you have nothing to lose and everything to gain.