Darn. Emotions run high over whether to bore guide or not to bore guide.
No doubt they are generally good insurance for keeping everything in line while cleaning, yet I've seen some serious shooters who are so meticulous about cleaning a rifle without a bore guide that no issues ever arise.
In contrast, there are some people who cram rods, brushes, and jags down bores as hard and as fast as humanely possibly, and for them, using a bore guide requires two whacks on a steel anvil with a rubber hammer to tear it up instead of the customary one rap.