You might look at
http://ecomodder.com/forum/showthrea...ion-33671.html
Permalink#3 has a list of thread to follow up, and Permalink #6 is someone who is actually doing it, although they haven't posted since April.
There's a pretty good PDF that quantifies things (volts, freq, etc.) but I can't seem to lay my hands on it right now. It said ganged electrodes are more effective than single ones.