To clean or not to clean? Silver French 1851 5 Francs Cérès

Not national preferences, it was actually global preferences. Ya see, from a historical perspective it's only been in recent years that things changed. And they haven't changed everywhere even yet. Prior to about 1960 most collectors worldwide routinely cleaned their coins, and most of the time not in a proper way. And it was pretty much everybody's opinion that that's what they were supposed to do.

Now there had always been collectors who didn't agree with that philosophy and would not clean their coins, but they were very few in number. But around 1960 those numbers began to slowly, very slowly at first, change. It wasn't until the 1980's that the concept of not harming the coins when cleaning them began to gain acceptance on a wider basis.

Today, there are still some people, worldwide, that see no harm in what is now referred to as improper and or harsh cleaning. To them, picking up a coin and wiping it with a cloth doesn't hurt anything. In other cases this is due to a lack of knowledge on their part, they don't understand, don't realize what they are doing to the coin with their actions/methods. And it wasn't, and in some cases still isn't always just ordinary collectors doing this improper cleaning. For example, in recent years, and they may still do it for all I know, The Smithsonian would routinely pick up the coins in the US Collection and wipe them down with cloths. Many other museums worldwide would do exactly the same thing, and some still do. Now they probably know better today but they also know that they have been doing it for centuries so doing some more really isn't going to hurt anything.

But you are correct in a way. Europe is one of the places where improper/harsh cleaning is still more widespread than it is elsewhere. Many dealers and collectors alike in Europe simply don't see anything wrong with it. And there are still those in the US that feel the same way, but their numbers are and have been steadily decreasing for some time now due to the ease at which knowledge can be disseminated in today's world.