Salt Water Metal etching 50 (Euro-)Cent Coin I want to etch the 50 Cent Euro Coin using this following technique that I came across on some DIY site: Immerse the coin and some disposable piece of metal in salt water such that they do not touch and attach current. Cover the non-to-be-etched parts of the coin with nail polish.

The article proposed to use a 9V battery block and used brass in their example. I understand the 50 Cent coin is made out of Nordic Gold: Is this etching method still viable, and does the 9V block deliver enough energy to at least remove the imprinting of the coin? Is there something else to consider (safety isseus)?

Unfortunately, I have no noteworthy background in chemistry. Thanks a lot in advance for any help.
ECM (electrochemical machining) is a safe (besides risk of getting electrocuted: keep your hands dry) way to carve metal. However, only electrically conductive materials can be machined. Both aluminum and copper are conductive, therefore you can carve it safely.