Scrimmy - depending on the metal - stainless or galvanised steel or Ali will determine what will clean it.
and/or weather its coated/plated/painted
if raw finish and is stainless get a metal polish - brasso might be lightweight - there are better metal polishing creams for this and i wouls also use a drill with 'mop' fitted this will take out lots of effort
the same goes for ali - but i would suspect it would have been annodised - if so i doubt you will get the shine back
same for galvanised steel as the plating/coating would most likely be damaged.
Darran