I'm always asking people why zapping is so much more popular then blood electrification and i usually get the answer that its just because its been promoted more and because its more comfortable.
In my opinion there is no comparison in the level of effectiveness, Blood electrification is far superior (I think even the people who sell zappers will admit this ;) ). I think zapping is wonderful but if someone is truly sick then why not go for the big guns... right? Blood electrification has a much better scientific basis as well as much better documentation of its effectiveness.
Since you were willing to try zapping then I think it would be a very good idea to give its older brother a shot as well, i think you would be much more satisfied with the results. Remember there are more precautions to take with blood electrification, such as dietary considerations.