Combine your baking soda and citric acid in a small bowl and mix to combine.
Add your lemon oil, lavender oil and peppermint oil a few drops at a time and mix to distribute evenly.
Next, you can add in your water a little bit at a time and mix to combine (if you add it too fast, you’ll get a fizzing reaction).
Scoop your mixture into your silicone mold and press down until your mold is full.
Let your toilet bombs dry for a few hours, then carefully pop your toilet bombs out of your mold. Store in an airtight jar until you're ready to use them.