How to remove Copper Oxide aka Green Rust the CRH way?

[GEOFF]

Hi folks, I got some silver coins with Green rust aka copper oxide, could pros tell me how to clean them from personal experience?

Sean? (thank you for the Pence help last time)

 

[synapse]

Ketchup!! cover it with ketchup for 10-15 minutes, then wipe off with a cotton ball or a q-tip. Repeat until all the green is gone.

Obviously this is not recommended for anything valuable...but if you're just trying to clean up some common coins, then this will do the trick.