Click on the photo for a larger view.
Wonder cleaner is a quick dip into a mixture of WHITE VINEGAR & SALT.
In the picture you can see the murky, cloudy liquid; that displays the oxides that have been removed from the copper during the cleaning process. This dip takes less than 1 minute.
Follow with a rinse of clear water and dry the pieces.
Hindsight, I should have taken a picture of the discoloured item. 😦
4 x 4 chain maille bracelet. 7 1/2 ” Copper, hand cut rings.