Coin Cleaning - Myth Vs. Reality

but acetone isn't cleaning as it does not affect the surfaces of the coin (it removes harmful substances and dirt, but it doesn't "clean" it).

Anyways... What is the consensus on Ultrasonic Treatments?

I'm browsing El Cazador coins rather regularly for my collection of 1782. While NGC only says these are genuine, so Details coins, they haven't ever put the word "cleaned" on the label. I do have to remind myself that these were all cleaned when coming off the ocean floor. I've seen NGC use "Saltwater Damage" in describing coins from unattributed shipwreck coins. These got cleaned too, even if just controlled fresh water water bath along the way.

But yeah, cleaned has a particular meaning in the hobby. Coins from the 16-19th centuries have almost all been handled and likely had debris removed at some point. The vast majority didn't make into a 2x2 until the last few decades, literally centuries after minting. They certainly didn't make it into a slab until the last couple decades. So they've all been handled and prettied up at some point along the way.

Lets consider the mother of all collections over at the US mint and Smithsonian ('33 Double Eagles, baby!). I bet that the use of gloves and other techniques to keep the dust off wasn't the original protocol as even the rarest of classic coins were coming off the presses back in the day.

Speaking of coin conservation... is there any way for the TPGs to remove minor carbon spots from copper coins?

from Thefreedictionary.com

clean (kl#275;n)
v. cleaned, clean·ing, cleans
v.tr.
1. To rid of dirt, rubbish, or impurities: clean a room; clean a suit.
2. To get rid of (impurities or dirt, for example); remove: cleaned up the trash; cleaned off the stains.
3. To prepare (fowl or other food) for cooking, as by removing the entrails or fat.
4. To remove the contents from; empty: cleaned my plate.
5. Sports To lift (a barbell) from the floor to the shoulders in one motion.

Sorry Child of the wheat but

is almost word for word the definition 1 and 2 of the word 'clean' when used as a verb.

This sounds way too much like my department head.

DH 'The currier who picks up your deposit does not count money. He just verifies it.'

ME 'How does he verify the amount of the deposit?'

DH 'He just verifies to make sure the amount is correct.'

ME 'How does he know the amount is correct without counting it?'

DH 'He makes sure the proper number of each bill is there.'

ME ' He does that without counting the money?'

DH 'Thats right, he verifies, but does not count the money.'

So, acetone removes dirt but does not clean.

everything in the universe is exactly as it should be

I use a bench grinder with a wire brush on it. Makes coins really shine nice.