You bet the little yellow sponge with the green fiber on one side left
it a little dull...those aren't meant to be used on any surface you care
about.
It's a little dull because the surface finish got scraped off.
Use the BLUE fiber ones...much gentler.

BRENT CHRISTENSEN wrote:
>
 Then I got up there with some soap and water
> and one of those little yellow 3M sponges with the green fiber on one
> side.  I used a light pressure and a swirling motion, and it removed
> the stains like magic without any harsh strippers, bleaches, etc.
>
> It also seemed to leave the surface a bit dull-looking,