Way back, I have seen dealers at shows rub some nose oil on a finger and transfer it to a well-worn coin to bring out faint details. Probably not a good practice, but far from rare.
I've only been collecting ancient coins for only a few years & I've personally seen a couple dealers rubbing nose grease on Roman bronze coins to enhance the contrast of the legends & devices. Sort of like brick cleaning but not so harsh.
What, exactly, was wrong with my post that was deleted. Would the mod that deleted it please PM me to explain? Thanks