Firstly, while I see what you're getting at, I don't think rock is a synonym for create or utilize in the phrase rock a rhyme or rock the bells. I think a more appropriate synonym is excel at or rule. I think this sense is also what we mean by "rocking the couch." — That couch is mine, I'm totally have the best sleep of my life on that couch, you have the bed, no problem!
This is the same sense as you rock! Yes, I ROCK THAT COUCH. OK, I'm being a bit facetious here, but you see why those two examples cited here as "origins" don't connect exactly with the rock the couch meaning.
It's hard to pin down when this sense of rock became to mean what you're trying to express, because there is no hard line separating that sense from the older sense. To rock has meant to dance/create music/party/excel for a long time. When can the "new" sense be completely extracted from the "old" usage, as the word gradually becomes used in nearly every situation? (qv. "nice")
Ultimately, this meaning of rock has its origins in the phrase rock and roll, coming from a euphemistic verb phrase common among Black speakers of english meaning "to have sex". (Move back and forth.) This hidden meaning appeared in song titles and dance styles since the early 1930s. Which gives, of course, a whole new meaning to the phrase I rock the couch.
I found this quote in an article about Scotty Morris in the August 1988 issue of SPIN:
A neighborhood basketball star, he called himself La Rock because the player who scored the most points in a game was said to have rocked it, rocked the party.