Oftentimes we overcomplicate some incredibly simple concepts, Locs are one of those concepts.
If we are talking bare minimum necessities required for a strong, healthy set of locs then I believe all you really need is water and oil.
This does not include whatever shampoo/soap you intend to clean your hair with. Other then that, water and oil. As far at the oil goes, you really need small doses if you are going to use it regularly. Using too much will evenutally lead to build up and blockage in your locs.
When it comes to the water, it could be a simple spray and dash or you can rinse your locs off completely .
The point is, you don’t NEED extra stuff to lock your hair. Anything extra will need to be thoroughly rinsed out at one point in time or another.
Sticking to the basics does have its benefits in the “loc” world. Water & Oil.