Old Army habits. I clean the same day they are fired.
I clean bore, chambers and exterior with Hoppe's No.9. Dry that off and oil heavily with my 50/50 mix motor oil/Three-In-One machine oil. Assemble and wipe down with dry paper towel or rag. (I use those blue shop towels from Auto Zone, which I believe are Scott towels.)
I use stainless steel bore brushes lubricated with Hoppe's, then dry patches, then oil the bore.
This has stood me in good stead for over fifty, maybe sixty, years. Don't think I'll change now.
Bob Wright