Back in great grand daddy's day, vigorous scrubbing with a bristle brush would harm the bore. Thev steel back then was pretty soft.
Weapons made after WW2 use better steel.
I wouldn't advise a stainless steel brush, but you can clean your bore with a phospher bronze or nylon brush til the cows come home with no ill effect.
History fails to record a single precedent in which nations subject to moral decay have not passed into political and economic decline. There has been either a spiritual awakening to overcome the moral lapse, or a progressive deterioration leading to ultimate national disaster.
If you think a strong military is expensive, think about what a weak one would cost