I feel the unsaid dialogue of the video was this...cleaning is fine..over cleaning is not.
Harshly 'cleaned' coins are not pretty to look at but bringing a buried crusty coin back to an acceptable visual level just makes it better for pics and posting and for your own personal display.
We all can say as detectorists we have learned by doing...we have saved some from the ground and we have made some better off left in the ground lol
It goes back to the skinned cat scenario....no one cares how it got skinned just that it is. So this journey shows his way of getting there.
The info presented shows us how to ruin a good coin more than how to save one and that is good advice to people who have coins that they would want to keep, show, and share.
There is a lesson for some in there.