Leaving it wet is a big contributor to dullness for the reasons you gave here. I would add accumulation of crap between the blades being the rest of the story.

Leaving it wet is a big contributor to dullness for the reasons you gave here. I would add accumulation of crap between the blades being the rest of the story. A small blast of air gets that crap out and leaves the shavings path clear for next time.