wordsmojo

Both proposed roots point at the same shelf. On Wikipedia's account the Kikongo mooyo names the spirits inside a charm and the cavity of an nkisi where the charm's materials sit — so the word starts as the inside of a container. On the Online Etymology Dictionary's account it is Creole, beside Gullah moco and Fula moco'o. Neither source claims the other is wrong.

The object has an ancestry that is not contested. Bakongo people of the Congo River region made medicine bags of leather or cloth holding feathers, animal parts, roots and herbs; when Bakongo people were enslaved in the United States the practice continued and became a custom of Hoodoo. Nkisi bags looked like mojo bags and are named as their ancestor. The philosophy came with them: in Bakongo religion, simbi spirits can inhabit an nkisi bag, and the nganga makes the bag for a person with ingredients specific to a particular simbi.

The bag has other American names — toby, lucky hand, nation sack, conjure bag, package — and the word hand in that list has its own contested origin: from finger and hand bones of the dead used in the bags, or from lucky hand root, favoured by gamblers, or from the hand of cards the mixed ingredients resemble.

Then the word left. Wikipedia's account is blunt about it: mojo underwent a semantic change in American popular culture at the beginning of the twentieth century and came to refer to sexuality and virility, as musicians began to use the word outside its original context within African American culture. From there it became motivation in general.

Inference — this is the sharpest case in this batch of a word walking away from the people who made it. A term for the spirit inside a container now means the thing a commentator says a footballer has lost and an investor says a start-up has found. The bag is still made; the word on top of it now belongs to everybody.