The problem with having a good borescope is that one may become fanatical about bore cleaning. I bought a good (for me) Lyman last year and have to keep the power supply in the house and the 'scope in the shop for safety reasons. Otherwise, I may actually check some pistol barrel that shot perfectly well at 200 yards and find it was actually filthy. I'd miss a meal or some sleep trying to get it back to like new condition and maybe get sick as a result.
Seriously, the .22 Kadet needs cleaning more often than any of my CZ 9mm centerfire pistols. My Kadet will fall off on accuracy in 500-1000 rounds, about the same time the chamber gets some buildup and starts dragging on the casings, causing feed problems. I can see chamber and leede crud with a borescope in the .22. And tooling marks when the crud is removed. And corrosion when the barrel is near the end of its life. Takes a long time, like 50k rounds. The 9mm/.45 cal barrels/chamber don't seem to be anywhere near as demanding.
Joe