With the timidity of "water" and "soap" (which are both EXTREMELY timid), you must be smitten with the old adage "Never clean your coins!". This saying must've been born out of horror stories of persons cleaning grandpas gold coins with ajax or whatever.
The truth is, it's a matter of HOW you clean them. Because for the kind of junk we md'rs sometimes find, you will get laughed out of a coin store, or anywhere when/if trying to sell.
Consider the following true example: There was a detecting mag. story many years ago, about an east coast hunter who had a few dozen large cents he'd detected over the years. He had never cleaned them (keeping with the old addage) aside from perhaps plain water rinse or whatever. One day, he decided to sell off some of his collection, so he took them all to a coin store that advertised that they bought/sold coins. He figured some of them must have value, because he could see from the coin books that a few of them were better dates, etc....
But when he got to the coin store and showed them his stuff, they nearly laughed him out of the store, telling him his coins were cruddy, caked, etc..... and offering him a mere pittance on a few others. So he asked them: "If I clean them up, then will you consider them?" They SHUDDERED, bristled and told him "NEVER clean your coins. That's an absolute no-no. If you do that, we will CERTAINLY never buy them".
The dejected md'r left the store, figuring all he had was value-less junk. He figured that he might as well get them looking better for some home display trays though, so he set about studying all the different methods for cleaning copper coins, w/o leaving any trace of the effort. After going through all the different pro's & con's for each method, solution, etc.... and after trying out various ones on common IH's and his common large cents, he settled on a way that seemed to leave no trace of effort.
After about a year, the man decided he would take these same coins back to the same coin store, to have them take another look. When he got there, he did not remind him he'd been in there a year earlier, nor did he tell them the coins had been cleaned. He was waited on by the same desk clerk ....... who apparently did not remember the earlier visit either. THIS TIME the dealer started offering higher prices, right off the bat. Doh!
I forget which cleaning method the fellow settled on, but the moral of this story is, that whenever you read/hear of someone saying "never clean your coins" (as no doubt someone will come on this thread telling you that very thing), you can see that this advice is not always right.
