Rem Oil, Birchwood Casey Sheath a.k.a. Barricade, Breakfree CLP, Mili-tec, WD-40, all of them work... The main thing before putting any oil in your barrel is do so with a dry barrel. Granted many of these oils have a water displacement ability, but why worry if they did the job. I use Birchwood Casey Sheath the most of all of these.