Clean fridge shelves which can't be removed?
You have to wash cleaners off, there's no other way to remove the dirt. The gunk is not going to magically evaporate, you will have to wipe. If your fridge is really dirty then I suggest a tub of soapy (dish soap) water, a sponge to clean and wipe, and a towel to dry. If it's not that bad then a kitchen safe spray cleaner and a sponge or paper towels will do fine. A pair of rubber kitchen gloves would be a good idea.