[clarkd]

My tweak on the referenced web page was to use an old PC power supply and a DC "voltage converter" that came from Amazon or ebay. I can't remember where, and someone with more knowledge should be able to tell you the correct name for the convertor.
Works without the Karo Syrup and the insects aren't attracted to your solution when you store it. I've used my setup to plate brake calipers. Below is a sample from the fresh air system with a yellow chromate wash.