How to get rid of bad odour in the fridge

We all know how annoying it is when we’re sure there is nothing in the fridge that’s past its BBD, still it stinks like a skunk. On one of these days, my 8-year-old nephew told me this one (he loves watching How clean is your house?):

Take a lemon, cut it in half, make a small whole in the flesh and fill it up with salt. Place it in the fridge and it will take the unwanted odour away in a day.