I'm surprised this question has not gotten more responses as I found this achievement to be very difficult and in need of some clarification. I just got it but can not tell you exactly what were the contributing factors were. Here's what I can tell you:
1) I was unsuccessful after many single player attempts and successful after my first online multiplayer attempt.
2) I chose my shots very carefully and let the other guy destroy everything as I had heard that accuracy played a part.
3) Neither of us used our A button attacks except maybe once or twice on the boss.
4) We either destroyed everything in the stage or came real close. Spread shot helps with this.