To actually more or less fully restore a metal from an oxide like Fe2O3, one would need an ion of hydrogen of aluminium. Acids can corrode the metal further by reacting with it and forming tough sulfates. What actually can unspoil iron is lemon juice and the citric acid in it -- a weak one -- that provides a lot of hydrogen ions if dissolved generously in water.
To actually more or less fully restore a metal from an oxide like Fe2O3, one would need an ion of hydrogen of aluminium. Acids can corrode the metal further by reacting with it and forming tough sulfates. What actually can unspoil iron is lemon juice and the citric acid in it -- a weak one -- that provides a lot of hydrogen ions if dissolved generously in water.
Interesting... I never knew that before! Maybe in v1.1 I can change the acid to include "(for restoring metal)" in the name.