Conclusions and Mistakes Made
1. Should have separated the pennies from the clad coins
2. Should have added the salt first, then the vinegar.
3. Do not shake in solution more than 5 min.
4. Doesn't work well on clad, but nickels do best
5. Should have rinsed the coins better
6. Could have used a smaller jar.
7. Do not use on jewelry or anything that will break.
8. Not good for coins already starting to corrode.
9. Do not leave sitting in the solution - rinse immediately.
A quick way to clean pennies - Original Recipe
A quick way to clean pennies is to put them in a jar. Fill about 1/4 of the jar with the coins. Fill the jar 1/2 way with vinegar. Add a teaspoon of salt. Close the jar and shake until coins are clean. It is very fast. Take out coins and rinse well, and I mean rinse well. Put on paper towel. Pat dry.
Not to be used on any coin of any value. The more difficult coins put in tumbler. - by George in Montreal
(He wasn't kidding when he said it was fast)
So, if you can't afford a tumbler, give this a try. But use a smaller jar, like a baby food jar and test it first.
NOT RECOMMENDED FOR BEACH FOUND PENNIES OR CLAD.
Here's a closeup of the results
You can see the ones that were eaten up already, did not do so well.