The disclaimer: I'm sorry to take such a hard-nosed stance in responding to items in this column as well as the "cleaning and preservation" one. As a coin collector since I was a child, I have to say that cleaned coins like the ones above just break my heart.
So here's something I remember as a general rule when I recover silver coins: The higher grade the silver coin is
A. The more damage you'll do to its mirror-like surfaces by cleaning it, and
B. The more monetary value will be deducted from its price tag as a result.
I never "field clean" any of my silver coins. Ample time to do that at home. Always with hard running water and at most a light going-over very gently with a camel's hair (extremely soft) make-up brush to coax any remaining dirt off. Those beauties in the original post at the top were worth well over $1000 each before the cleaning. Hard to tell without examining them closely how much value was lost by the process. Just a word of caution for everyone. We are the saviors, caretakers, and in some cases sellers of the historical items we've recovered. We are responsible for their survival and preservation for future generations. I've seen way to many "field cleaned" silver coins here. Hopefully we'll get the word out to everyone not to take the risk. Charter members, I'd love to see treasurenet take an official stance against field cleaning silver coins. For a site with so many wonderful possibilities as far as education, I think it could only help the situation. At this point it is obvious that we as an online community are not educating as much as we could be.
-Buckleboy