I was going to say that sexual agency is mojo, but it appears that a mojo is a magic charm and that I misunderstood what Muddy Waters meant by "I got my mojo working." The notes at Wikipedia claim, "The bag or purse-like mojo symbolizes female genitalia, and in this very sexualized sense, mojos are more often associated with women than with men." No wonder I'm confused! But perhaps this simply confirms what you found via Google.