Cleaning shower grout is a vital household task to prevent mould, which can be difficult to remove once it takes hold. Leslie, a cleaning expert and founder of Lemon Grove Lane, warns against using bleach for this purpose, as it can damage grout and is ineffective against deeply embedded mould. Instead, she recommends a mixture of 120ml of baking soda, 60ml of hydrogen peroxide, and 10ml of Castile soap. This combination not only penetrates the grout effectively but also prevents mould from returning. Hydrogen peroxide kills mould spores, while baking soda's abrasiveness helps the solution reach deep into the grout. To use, mix the ingredients into a paste, apply it to the grout, and let it sit for 10 minutes before scrubbing with a stiff-bristled brush. Rinsing and drying the tiles will result in a clean, mould-free shower without the harmful effects of bleach.