you misunderstood my intent to explain seasoning...just used skillet as example, my barrels are perfect and no carbon buildup like a frying pan that you alluded to in any of them..
Of course I know the barrels are not cast iron, but on a microscopic level you do need to season them the same, period as all steel has a certain amount of porous surface whether super hard or not!!! I broke in a brand new airplane engine in 1998 from Lycoming and they told me same thing, I used a break in formula from them to coat and season the cylinders as all metal is porous to a degree.
I quit using detergent years ago, just plain hot boiling (almost) water and while still fairly warm run a patch with liberal amount of bore butter after drying thoroughly with dry patches and heat, or any good well known natural lube and while hot it disperses the bore butter into the entire area of the barrel, just works for me and I have never had a problem with rust whatsoever. I only use Goex BP and all the fouling comes out with water only....NO Detergents. I have noticed rust after using detergent almost immediately and on my own I decided to quit using it years ago.
I also spray generously T/C #13 (aerosol can) oil not the bore cleaner, but the #13 oil in aerosol can in a rifle that I am not goiing to shoot for awhile and put patch between hammer and nipple to catch excess drip of oil, if it is new barrel then I use the bore butter and I check barrel several days later and take care of it if there is a sign of rust or anything off color. I read a military manual that said to clean fouling from BP rifles with plain water and it didn't have to be warm either as water alone will remove fouling.
Respectfully,
jim