Mix baking soda, liquid soap and hydrogen peroxide in a medium-sized glass container until it forms a paste-like consistency.
Add tea tree oil or essential oils of your choice.
Spoon the scrub cleaner into a jar with a lid. Seal the jar. This cleaner will harden when exposed to air for a prolonged period of time.
Notes
Cleaner can be used immediately and kept at room temperature (in a sealed jar) for several months. Use the polishing paste all over your tub surface for a sparking clean tub.