Been using bore-scopes since 2007 and occasional use since 2001, for both customers barrels and my own barrels.
About the best thing they have done for me is to teach me how to clean and maintain a new barrel through it's accuracy life span.
They have also taught me how to attack and go at barrels that have been neglected, which often need there own unique individual ritual.
Can agree some what with input like
@Link wrote above, in that some barrels after certain amounts of neglect and/or wear, may very well not benefit from a "super cleaning". What I have consistently seen is from the time a barrel is new, if it is cleaned often and down to "shiny blue steel" every time it is cleaned, the throat and rifling do not erode as fast, accuracy is more consistent, and they clean out with less effort and ritual. Which is why myself clean my own barrels at the end of each day, no matter if I fired 5-rounds or 105-rounds (they get put away clean and oiled). And "shiny blue steel" from day one until I retire them, is my goal. Ran-over fouling, is what layers, erodes, and harms barrels the must - IME.
I'll suggest to those new to a bore-scope: rather then looking for faults and erosion in barrels, concentrate more on developing cleaning rituals, techniques, and learning what all steps, procedures, and cleaners will work best to fulfill your own demands and needs. Perfect cleaning methods to maintain new barrels through there life, as well as for experienced barrels (which can need uniquely different rituals). Find what works best for factory barrels/rifles verses match grade barrels, both new and used.
Note: barrels that are badly layered with burned-in carbon, it's not necessarily important (or even practical) to get it all out at once, just not to let it get any worse, and maintain it better in the future. Have seen barrels that looked pretty horrible inside, that still shoot very well.
My 2-Cents