There's a major difference between "drill sergeant clean" and how clean the weapon needs to be to function perfectly. Both the Army and Marine Corps use rifle cleaning as a
discipline tool to emphasize attention to detail, etc. In reality the weapons will function perfectly at a much lower standard. Taking rifles into a hot shower with a brush and kitchen powdered cleanser will get them very clean! (Now, who wound ever do that?!

) It ain't good for them though.
The need to eliminate "copper fouling" in the barrel, for example, ended circa 1950 when the last corrosive primers were produced for the M1 Rifle. Corrosives can be literally plated over by the copper and eat the barrel underneath. Copper fouling in center fire calibers is self limiting and right back the first magazine after you've spent hours of cleaning. Fully chrome lined bores in modern (circa 1968 and newer) weapons are immune to the problem to start with. Derrick Martin (Accuracy Speaks) insists that it's not necessary to remove the copper from National Match rifles (as at Camp Perry). 1 MOA accuracy will win the National Matches if you do your part.
.22LRs don't get copper fouling to start with and there is no need to clean the barrel at all. I do drag a Bore Snake down mine, though. The same Bore Snake I use in my 5.56mm weapons.
Upper and lower receiver cleaning is CLP and a brush. Wipe the reside out with the shop towel.
One thing to be absolutely avoided is disassembling the lower receiver and pulling the hammer and trigger for cleaning. There may be times this is necessary, but routine pin removal and insertion in a polymer frame is probably going to cause more wear than in a forged aluminum frame. Trigger/hammer removal is not authorized at the soldier level with the M16-family.
Cleaners line Simple Green will eat aluminum parts. "Dry" lubricants with graphite in them will do the same.
RLTW,
-- Chuck