This is something that has been on my mind for years now.
Now more than ever it seems that just about every raw coin that is 100 to 150 plus years old is stated or slabbed to have been cleaned.
Now this is a really broad subject but wanted to start it off.
I think the average mindset with either dealers or graders (Tpg's)
as well as most others is that if a circulated/worn coin has some darker areas in the small field recesses away from the devices that is has been cleaned. I'm not talking about any coins that have obviously been polished or chemically cleaned. Could the higher areas that are prone to wear be just that. Normal wear ? and not cleaning. I think so on most. What are the determining factors on cleaning ? Cleaned, (that alone could have a hundred diff. causes) improperly cleaned, harshly cleaned etc. And who determines them.
Does the grader seated at his/her desk do both the grading and cleaning determination. I think the cleaning aspect is just as complex as the grading aspect. If a VF 150 yr. old coin with normal wear, say being handled, carried around in pockets etc. has some normal rub is that cleaned ?. Technically any coin that came in contact with water, dirt or anything for that matter could be said to have been cleaned. Do not want to make this first post a Novel here but maybe you get my drift and can fill in as we go along. As well as myself doing the same. I just see a lot of nice non BU coins out there
that are scoffed at in the raw. Not me, the coin

I personally (not bragging here either) have had some knock down drag out brawls with dealers and others about some raw (at the time) coins that I have owned, sold and kept etc. over the years. Any and all stated CLEANED.
They were all DEAD Wrong. At least as far as the slab later stated.
That also (TPG's is another subject on the subject)
Worm can is now open.