How do I clean my new second hand fridge to ensure it is germ free?

My fridge finally broke. My landlord agreed to give me a ‘new’ second hand one from another of his properties. It has arrived in a filthy state. The actual fridge is fine but the previous owner hadnt used it for a while and had it sitting in its scum. It is horrible to look at because its very dusty and she smoked so its gots its own sort of auroa of that around it! I can see its a good fridge underneath all that but I need to give it an excellent clean. What can and should I use on a fridge to get it clean and useable again? Is there any products which should not be used on fridges?

Thanks