Do salt water clean pennies?

The cheapest (but more complex) way is to use reverse osmosis, which produces two water streams... one with less salt, and one very concentrated in salt (perhaps toxically so) and "floaties" that...

Nope. Stick a penny in some coke or pepsi (Coke preferred) and wait like an hour or two (im not sure maybe a day if you don't see any progress) and voila! A really clean penny.

not if you just soak it in but you can put this washing up liquid on it (I'm not sure which brand it was) I know this works because I did it on a filthy roman coin I found buried in the garden

A dearly Kid, Carlos

Well i just did a project on "what will clean a penny better warm water, vegetable oil, or No caffeine soda" and warm water won! I'm not sure why it won but i think it won because water is natural...