If you disrupt the electrical connection between the prop and the zinc, you may indeed slow down or stop its corrosion. However, you've also defeated its purpose, as something else must become the anode. The stainless parts within the prop are not electrically connected to the shaft zinc.My suspicion is that the proximity of the bronze in the prop accelerates the prop zinc consumption. Even given the shaft zincs are there... Next time you pull the boat you could try slathering the prop with a dielectric goop, but I have had mixed results with this.
