| Step | Action | Purpose | |------|--------|---------| | 1 | Flush toilet to wet bowl surface; reduce standing water. | Prevents immediate dilution; exposes stains. | | 2 | Sprinkle ½–1 cup baking soda evenly inside bowl, focusing on waterline and sides. | Abrasive coverage. | | 3 | (Optional) Spray with white vinegar for fizzing reaction (sodium acetate + CO₂). | Enhances loosening of limescale; do not mix with bleach. | | 4 | Let sit 15–30 minutes (overnight for stubborn stains). | Prolonged contact time. | | 5 | Scrub with toilet brush, paying attention to rim jets and under the rim. | Mechanical removal. | | 6 | Flush to rinse. | Removes residue. |