I say, and with God's help: It can only be purified by washing, and it cannot be purified by drying like the earth; because the purification of the earth by drying is established contrary to analogy, so it does not extend to it as long as it is not connected to it. Refer to: 'Umdah al-Ri'ayah p1: 139, 'Naf' al-Mufti p153, and 'Al-Bahr al-Ra'iq' 237, and God knows best.