but...
If people don't chelate after using sodium hydroxide based relaxers, then the mineral in their hair is sodium...
True there is some level of sodium left in the hair, but it is important to realize that there is always some level of several minerals in the hair. Generally the level of sodium left in the hair isn't significant enough to need chelation every time, because the other minerals already in the hair will balance it out and the formulations for relaxer after care are made to maintain that mineral balance.
While calcium hydroxide (no lye, which leaves calcium behind) is known for dryness, sodium hydroxide (lye, which leaves sodium behind) is known for leaving the hair moist...
I think in this case "moist" is relative-when in comparision to a no-lye relaxer, then yes lye leaves the hair more "moist". A chemical process that is introduced to the hair has two main functions 1) to open up the cuticle to make processing possible and 2) to process the hair in the desired manner. As I stated before sodium is a water softener, so when relaxing with lye, soft water is introduced into the hair shaft, however this does not detract from the corrosive nature of sodium- which is why gloves are used during the process. Calcium on the other hand can harden water (an example of this is pipe calcification in hard water areas). The added "moisture" is due to the softness of the water, not just the sodium itself. This effect however is very temporary, oftentimes going away by or before the next wash. Anyone who is relaxed can attest to just how dry the hair can get regardless of which process they used.