I agree with Axxe55, Naphtha, BillDeShivs is right, You guys are over thinking this !.............
When all else fails.
How about when your being dumb, put your ar in its soft case with a hot barrel, and melt the lining to the barrel?
And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war.
little WD40 and some 0000 steel wool should be good to go.
Won't Hoppes remove it?