Apply the damp stone to the world. Applying mild tension, rub inside of a circular movement until you see the dry pores and skin removed. Porosity: Pumice is very porous, with around ninety% of its volume consisting of empty spaces, rendering it a wonderful substance for water retention in horticulture. https://edenproductsltd.co.uk/2025/04/17/the-history-of-pumice-stone-from-ancient-civilisations-to-modern-day-uses/