Combine baking soda, 1/2 cup water, and the essential oils you have chosen into glass bowl.
Stir together with a metal spoon.
The mixture should resemble damp sand, so add more water, a little at a time, if needed.
Divide mixture equally into silicone mould and push down with your fingers to compact it.
Allow it to rest 2-3 days or until mixture hardens.
Once hard, place in refrigerator to help eliminate unpleasant odors.
Store additional fridge deodorisers in an airtight container until ready to use.
One disk will last up to a month in your fridge.
When replacing the deodorisers, don't throw the old one out. Place it on the plug hole your kitchen, bathroom or laundry sink and pour a little vinegar over it till it fizzes and then disappears. Pour a litre or two of boiling hot water down the hole to clean out your pipes.