Fridge cleaning checklist
Clean the fridge in order: planning, sorting food, safe defrosting, the door seal and the drain hole. The list adapts to frost-free and manual-defrost models.

[ ] Pick your moment and prepare somewhere for the food
    A full clean with defrosting takes hours. Prepare a cool box, a bowl of ice or a cold spot, and start when the fridge is not full.
[ ] Take everything out and check the dates
    Check every package, not just the front row. Bin anything expired or long open, and group the rest by zone so it goes back deliberately.
[ ] Switch the fridge off or set the mode the manual specifies
    The method depends on the model: some have a service mode, others are simply unplugged. There is no reason to clean the interior with the power on.
[ ] Take out shelves and drawers and let them warm up
    Glass shelves from a cold compartment must not meet hot water straight away: the shock can break them. Leave them out while you clean the interior.
[ ] Let the freezer defrost naturally
    Open the door and put a container underneath for the water. Do not speed it up with a knife, screwdriver, hairdryer or boiling water: that damages the walls and the evaporator.
[ ] Clean the interior from top to bottom
    Use a mild cleaner or a weak baking-soda solution, then go over it with clean water. Abrasives, bleach and strongly scented products do not belong here: the smell transfers to food.
[ ] Clean corners, shelf supports and door bins
    Drips that later cause smells hide in the grooves and supports. Door bins are easier to wash separately once removed.
[ ] Clean the door seal and its folds
    Wipe the folds with a soft cloth or brush and dry them. Do not stretch the seal or treat it with oils: a poor seal means more ice and more energy use.
[ ] Clear the drain hole
    Find the hole on the back wall of the compartment and clear it the way the manual says. Water at the bottom of a fridge nearly always means this is blocked.
[ ] Wash and fully dry the shelves and drawers
    Wash the warmed-up shelves in warm water. Put them back only when dry: moisture under a drawer soon becomes a smell or ice.
[ ] Wipe the back wall and keep the air vents clear
    In a frost-free fridge the air has to circulate. Wipe the wall and, when reloading, keep packages away from the air vents.
[ ] Wipe the door, handle and sides
    The handle is one of the most-touched surfaces in a kitchen. Clean it and the top of the door, where nobody looks.
[ ] Remove dust from the condenser coils at the back
    Do this with the power off and only in the way the manual allows. Dust on the coils reduces heat transfer and makes the fridge work harder.
[ ] Switch it on and wait for it to reach temperature
    Let the compartment cool to its normal temperature before you put the food back. A warm, fully loaded fridge takes much longer to recover.
[ ] Put the food back by zone
    Ready-to-eat food higher up, raw food lower down and covered. Label open packets with a date so next time you are not guessing.
[ ] Write down what you threw out and what to buy
    While it is fresh, note the shopping and anything that spoils regularly. That is the only way to avoid repeating this clear-out next month.

Checklist from Unload: https://unloads.me/c/fridge-cleaning