Magic eraser and water=awesome.
Well - no one could be interested in "altering" the hue or original shine of the plate - eh?
Just clean (soapy water or windex) and wipe gently with a soft cotton cloth afterwards.
"neverdull" - Hmm... I suppose it'll mar the surface quite much....do not use it for cleaning af Marantz faceplate.
Do all remember, what they looked like when new?