Soak your hair thoroughly with water, then thoroughly wet the shampoo bar to activate the ingredients. Swipe the bar a few times across your hairline and scalp to deposit the product — as an alternative, you can rub the wet bar of solid soap to create a rich lather and apply to your hair. Use your fingertips to massage the soap into your scalp and roots, working outwards. For long hair, you can also smooth the lather down the lengths. Rinse your hair with plenty of water, working in sections to ensure all product is gone, preventing a residue. Repeat if needed — if your hair is very oily or you have recently switched to shampoo bars, a second, quicker wash can help. Ensure you keep the shampoo bar on a suitable soap dish in a dry, well-ventilated spot to prolong its lifespan.