Empty the contents of your bag and remove dirt.
Use a white cloth (or clean white sock if you don’t have a white cloth at home).
Soak the white cloth in warm water with mild washing detergent added.
Gently rub the bag to remove dirt.
Rinse the cloth in clean water and wipe the bag gently until all the detergent is removed and your bag looks lovely and clean.
Leave your bag to dry naturally by hanging it up.
Voila- your bag should be as good as new.