Okay, you know those holes that are on the inside of the frame, gas holes I calls them, places where air can escape when the tubes are welded, well myself when in maintenance mode with the spray lubricant in hand with the straw attached, I squirt liberally down those holes, not just at the back wall, but the straw is forced at right angles so a layer of oil is deposited inside the frame. Not forgetting the other holes where screws mount, the bottle cage area, undo a screw and squirt in, create the vapour and allow the vapor to settle where it does. Forks removed periodically for bearing attention, hey , more holes exposed for the mean old squirty oil and similarly the exposed inside of the front tube, even the front forks get it down the steerer and up through the gas holes. Then there is the seat tube, remove the seat pin and squirt away, but for those with under BB cable runs the thing the cables run in if screwed to the bb, remove the screw and watch water run out, then when that's done squirt some oil in.
But then there is waxoyl but doesn't that add weight ? But of chromoly, it seems not to rust fast, perhaps the chromium in the steel is a rust inhibiter, as I have scraped paint down to bare metal and weeks it has been before rust started to appear.