I talked to my Sensei this evening about your 'sun and moon' reference. He didn't mention anything about a specific technique being called that, but he did say that the sun and moon is an aspect of the kata itself, referring to the In Yo or hard soft balance that is focussed upon within the form. The 'Sun' being the hard aspect (outer area of the limbs that are used to protect the 'Moon' or softer, under areas of the body and limbs.
Sorry I could'nt be more helpful, I know this answer can be seen within pretty much the entire Goju system's forms and philosophy. I'm sure I probably hav'nt mentioned anything here that you did'nt already know.
All streams flow to the sea because it is lower than they are. Humility gives it its power.