the juice of two lemons to a litre of water  , soak a soft cloth in it and wipe it over the steel. Then, as usual,

dry everything with a soft cloth. For an even more intense result, you can wet the sponge, already soaked in lemon, in salt and then wipe it over the surfaces to be polished.

The use of coarse salt is not recommended  because it could be too abrasive and

therefore scratch the surfaces  . Finally, it is best to avoid using too much salt, which can ruin the steel.