No one sees my back most days, so I'd take that opportunity to use something I could leave on, like a patch or strip. It would treat the acne (but still allow my skin to breathe) and protect it from outside bacteria. The patch would be comfortable and movable, and when I take it off, my acne would be significantly improved (or on its way to be). Maybe I'd use this once or twice a week, and then I'm good to go.