I have not yet heard any complaints about the way I approached "black smear correction" in Titans of Space DK2, and it seems to be fairly effective as a temporary solution until Oculus can provide a workaround/solution as part of the SDK/hardware itself. Even so, I'm not claiming that this approach is ideal in any way.
Below is a Unity package containing a simplified version of the black smear correction I am using, which essentially is just a brightness and contrast adjustment. The default values are what I'm using in Titans of Space, but you're free to fiddle with this to see if you can find something more optimal for your own scenes.
Simply import it into your project and inside the BlackSmearCorrection folder you will find a README.txt that contains short instructions on how to use.
Hope it helps!