Now, after doing some thinking, could this be a good idea?
Run a diatom filter til the water is crystal clear. If the GW comes back, do it again and when the water is crystal clear, do a 3 day blackout. I think this could eliminate the having to do the extra PWC's before and after the blackout, as the water will be clear and you are just killing off the little bit of remaining GW in the tank?
Just ordered the Vortex Diatom Filter- XL. How often do you need to change out the filter bag? Can it be rinsed out and reused numerous times, or is it once it's plugged up, it needs to be replaced?