I was told by Ken of Madpetz that the all-in-1 bio pellet actually incorporate the GFO into the pellet. So when the starch get consumed by the bacteria, the GFO is slowly released and absorb the phosphate. The GFO particles are then picked up by your skimmer same like the bacteria.
I was using NP biopellet before switching to the all-in-1. Before that, my skimmate is lighter in tone. After switching to all-in-1, I realized the skimmate color is darker. I believe this is due to the GFO.
Don't ask me whether it is effective or not as I have just started using it. Only time will tell.