Pour the washing soda and citric acid into blender and pulverize (my washing soda was chunky so needed to be softened so you may be able to skip this step).

Pour both into large bowl next to your silicone mold.

Add in essential oil drops and stir.

Using a one cup measuring cup, I slowly added water while stirring. It fizzles a bit when you pour the water, but keep adding and stirring until it clumps together.

I poured and patted these clumps into my silicone molds (it made 11 of them...that's 11 times I don't have to use elbow grease to clean my toilet!), let them sit overnight to harden and store in a glass container next to the toilet.

When ready to use, put one in the toilet, walk away and wait until it dissolves. Gently wipe away edges with a toilet bowl cleaner and flush.