Alex,
When I get mine isolated and can confirm that it works as advertised, I'll post all the necessary parts, photos, and description of the process.

In the meantime, I'd recommend that you get a reference electrode and check your hull potential with and without your engine and genset running. Here's one at BoatZincs:
http://www.boatzincs.com/corrosion-reference-electrode.html

On our Amels, with the reference electrode in the water and connected to the negative post of your multimeter, and the positive electrode of your multimeter on your bonding system, your hull potential should read between -900 and -1050mV. If it is more positive (less negative, say -700mV) you are under protected and should look for a source of electric current leak. If you get a reading more negative (say -1200mV), you are over protected and can have problems with bottom paint or other issues less dramatic than electrolytic damage to your prop shaft or thru-hulls.

All metal exposed to saltwater should read the same potential if they are properly bonded to the zincs. If not, check the connections of your bonding system.

More in a week or two (I hope),
Kent
SM243
Kristy