Lemon juice makes a useful household stain remover, disinfectant and deodoriser.
You can clean glass shower doors by applying lemon juice with a sponge, and then shine dry with crumpled newspaper. You can remove ink from clothing by applying lemon juice on the ink stain, and then washing as usual. To remove fruit and berry stains, as well as the smell of garlic and onion, rinse your hands with lemon juice. To remove tarnish from copper or brass, rub a cut lemon with salt and use as a scrub.
Finally, lemon juice can be used to enhance the flavor of foods – allowing you to use less salt in your cooking, and to ditch any artificial flavorings.
Source: the Enviropaedia