I scrape, brush and vaccum the inside of my stoker stove along with removing the grate, hopper and feed assy. and cleaning them also. I remove the doors and leave them off until next season.
My stove is in the basement with a dehumidifier also. Tried the WD-40 treatment one year but didn't like the smell/smoke when I fired it back up. Haven't used it since and have had no problems with rust in at least 10 years. If your basement is dry and the stove clean, I see no need to apply anything.