I was walking by an arms room today and saw soldiers cleaning weapons with sandpaper and steel wool inside and out to remove rust and carbon.

I about had a stroke...

Steel wool and oil is ok, sandpaper isnt.

The military does more damage to weapons cleaning them than they do firing them.  I've cringed many times seeing what troops are doing to their weapons but, as long as the leadership expects absolutely spotless rifles, troops will do whatever it takes to get there.

Quoted: The military does more damage to weapons cleaning them than they do firing them.  I've cringed many times seeing what troops are doing to their weapons but, as long as the leadership expects absolutely spotless rifles, troops will do whatever it takes to get there.

That's right. I think that's where a lot of the over-cleaning compulsion gets justified.
If the military does it it must be right.

AR's gas system does put fouling where it's real obvious and pride of possesion tends to motivate some real aggressive cleaning. Most shooters don't get to shoot as much as they would like to and lots of cleaning let's them handle their pride and joy.

It's mostly harmless till you get to sandpaper and steel scrapers.

Sandpaper?  That's a new one for me.  I'll have to keep that in mind next time.