- 1 cup baking soda
- ½ cup corn starch
- 20–30 drops essential oil (such as RC, Thieves or Wintergreen)
- 2 tbsp water
- Mix the baking soda and corn starch in a bowl and whisk.
- Continue to whisk while adding essential oil. Slowly add water until mixture sticks together in a ball. (Mixture should hold together when squeezed but not appear wet. Add more water if necessary.)
- Press mixture firmly into an ice cube tray or silicon mould for at least 24 hours or until hardened.
- Remove and store in an air-tight container.