For those who live in the Eastern part of our Countries, I suggest you use something that ranks highly in any rust-tests. Humidity is your enemy.
Around the Great lakes is VERY bad, humidity wise.
When I lived back there, I just used Hoppe's #9 Solvent. Seemed to work for me in all of my suppository rifles over the years.
Out here in the West, the average humidity is 50%. At rendezvous B.C., the humidity will run from 6 to 8 & up to 70 % or so when it's raining.
We do get humidity upwards of 90% here in a downpour, but back easy in Southern Ontario, the humidity will be 100% with not a cloud in the sky
and over 100F temps. That is hard on rust preventatives trying to do their job.
Again, maybe it will be the last time, but I doubt it, Bore Butter seems virtually chap-stick with camphor oil added for the nice smell. With loose patched
loads, it will actually build up in the bore and be hard/difficult to remove. The stuff that builds up, will have BP fouling under it = pitting.