These things really work-- excellent for restoring a truck interior to tip top look- especially those grimy driver door panels- with grease/diesel black.

Yes, they do work, but they will turn a glossy surface dull.

you must be scrubbing really hard-- or no one's ever cleaned there before.

Their own instructions on their website:

"Not recommended for use on surfaces that are polished/glossy, or on brushed, satin, dark, or faux finishes."

I love the Magic Eraser. I always have one handy.