I did see this idea a year or so back, it's what I called garage-class EDM, or Electronic Discharge Machining. My procedure was pretty much the same, with about 15 or 18 volts of DC current, and a capacitor. Made a great sparky noise when I zapped the hole into .002 brass, but the hole were very crappy, with loads of garbage around the edges. The holes were not clean, but let the sunlight hit 'em and you got great diffraction rainbows. The finest crappy holes I've ever made! Maybe I needed a finer needle and a thinner material to blast...
Michael Georgoff San Jose, CA
