If they were dateless then you did not murder them - maybe just put a kink in the oxygen hose. These coins actually look like ones that this one seller on ebay used to list all the time. I don't know a fix for this, but it does remind of some of the nic-a-date nickels.
I didn't say you were. Think of it this way: you heard that adding salt would help, but are obviously disappointed with the results. Now turn it around of how someone else could feel if they took the blanket statement that "soaking coins in vinegar is totally fine" as fact and ended up in the same position. The only point was that even with all the poor information available online, we should not contribute any more to it. As for any suggestions, there is not much I can offer other than to say this is a good opportunity to experiment; just don't use the same method on all the coins at once. Switch it up and try different methods on different coins. Kentucky gave fine suggestions, but if nothing helps, you could always grab a bottle of nic-a-date and go to town with it. Tsk, tsk, tsk.... believe it or not, there is a difference between being unwilling to sugarcoat and being condescending.
I would say buy nic-a-date and soak them until the spots come off, and just use this product on the date area in the future. Just my opinion.
Ok guys,be nice. This is a preteen,looking for some help. We should be encouraging our youth. We all learn by asking questions. That's why we're,right? Hang in there,TC.
Acid is my best guess to dissolve whatever is on the coins. Someone with a little chemistry knowledge could probably figure out what it is and if there is something else that cold dissolve it or reverse it. You've got copper and nickel in an acidic solution of sodium and chloride ions. it seems simple enough.
you should read this thread. http://www.cointalk.com/t221469/ salt is bad, and as the vinegar evaporates, it concentrates its awesome power
Hang in there, but do not ever use anything but acetone, alcohol, or hot water, and air dry, electrolysis, might, and I repeat might be the next step.
Well, haven't you heard of "too many cooks spoil the broth"? That said, it's always important to experiment with one if you are doing something different - don't do a batch of them at once. I believe with vinegar and salt, it would have corroded the coins.
I've found that toothpaste and a toothbrush works on mildly corroded coins. Although it could just be the toothbrush working.