Doesn't using the magic erasers dull the finish to an almost matte-like look?

I had a 512K that I ruined trying to retr0brite. I made the solution way too strong and I cooked the thing. It was all white and ashy. I took a fine grit sandpaper to it thinking I could just take a thin layer off the top to expose the beige underneath, but the whole thing looked terrible after that. The sandpaper basically made the case smooth. It removed that bumpy/textured finish that it had and left it with a dull-matte finish.