I used a Rerun Peacock (around 764 FS) with Good Fellows, George's Day Out, and Impending Doom (all Level 6 Gold moves) and an unlocked ground combo/character ability. Start by blocking (never attack first), and block until the opponent finishes hitting you. For me, I threw the opponent and swiped down to hide immediately after to avoid damage and BB1/BB2s, and repeated this until I was able to use one of my blockbusters. When I could use them, I threw the opponent, used the blockbuster, then immediately swiped down to hide. If your opponent stays blocking the whole time (like what happened for me when I beat this), you could possibly avoid a BB3 because it may not be fully charged, and it will be easier for you to use the throw/swipe down method to defeat the stage. So, it also depends on luck with the opponent's loadouts, as mentioned above.
I have also heard of people using only Georges to defeat this stage, but I'm not sure if the method is still effective after the latest update with the George nerf.