The battery worked for me, but it was definitely just etched, not deeply engraved like lex2006 and VashHash in the pictures above.
If you use batteries bank them together it will go a lot faster and also load the water up with lots of salt , warm water will help dissolve it better too. If you are using power supply at 12 volts try it about 6 amps , it will start to sizzle quickly, the q tip will last about 15 secounds and turn ugly stinky brown color chuck that out. The dirty will cause your etch to turn black. And do not breath these fumes, very very bad fumes.
