Add it to 1/4 of a cup of the castile soap. It will gel up immediately. Use a fork to stir it together. Don't worry if it stays clumpy; we’ll fix it later.
Combine the remaining tablespoon of castile soap with vitamin C powder, charcoal, preservative, and tea tree essential oil in a separate bowl.
Stir until the ingredients are fully incorporated.
Transfer to the soap and water bowl and mix with an immersion blender.
Transfer to an airtight shampoo bottle for storage.
Notes
Use this product 2-3 times a week until you notice your hair is free of buildup and is lighter in texture. After that, use it once a week or as needed.This amount fits perfectly in the shampoo bottles linked above.If you wish to use your own preservative, make sure you follow the instructions on the packaging for proper dilution.If stored correctly in the bottle and away from sunlight, this shampoo should last for up to 6 months.I’ve included step-by-step images in the post above for visual guidance.