Every wonder why birds can sit on a 12,000 volt power line and not die? It is because there is no current
(electrons) flowing through their bodies.
I imagine the same exact thing would happen to any biological fouling that wants to attach itself to your hull
...even if you hooked up the electrical
output of a nuclear power plant to your hull
Any sort of cathode (by convention and not electron flow) you hang over your hull is going to send current
straight to ground first and not to something attached to your hull first and then to ground, anode, negative or neutral....whichever the case may be.
Electricity takes the path of least resistance which will not be through fouling first. Interesting idea, but fouling is not a resistor/load in a closed circuit.