The 'experiment' was extremely half-a**ed. I used salt simply because I couldn't be bothered to get the NaOH from the shelf, and the experiment was only intended to last five minutes, and the room is extremely well ventilated, my skin is like an alligator's and my lungs are made of stainless steel.
I wired a 12 Volt battery via a voltmeter for the simple reason the volt meter has croc clips so I could easily connect some power to the disks.
I know about the chlorine risk, but thanks for the warning anyway.
* But could you answer the question about the missing coating from the anode, and the yellow-green scum on top after I called it quits, please?