I can't recall if it is 5 or 6 diodes used in the store bought activator button, but it is about that number. I think it was 5 and a 6th strung in the opposite direction parallel to the string of 5. I also think they used 6 amp diodes, so you'll want to make sure that whatever diodes you choose to use can handle the current draw of your set-up.
Another option, though a little more involved could be to rewire the rectifier in the ZW with a switch that allows it's polarity to be reversed, though this is more of a passing idea and I'm unsure exactly what would be involved.
JGL
