Dang, that's pricey! The one I linked to for $19 (same place I got mine) is 14oz, but perhaps most of the cost of the AMZ one was for convenienceI bought a small container of Aeroshell 33MS from eBay. Yes it was expensive, ~$7.00 for about 1/2oz, but it will last me a lifetime. I have only put one barrel on an upper but I have enough to do 15 more. I also don't have a huge tube to deal with in my garage or gun room.
I use scientific terms like that all the time...lolscrubby motion'.
Permatex nickel
It works on motors up to 2500F, so why not rifle barrels. There is copper also, but not recommend on stainless
If I'm remembering right, copper base is for cast iron to cast iron. Like boiler fittings. The aluminum base is what's used between aluminum and steel. I don't have experience with the nickel based. But at 2500 degrees, the upper will be liquid. It has a melting point around 1220 degrees. I'd suspect nickel based would be used on exotic metals like titanium but I'm not positively sure.