Sayyiduna Amr bin Bujdan (may Allah have mercy on him) said that he heard Sayyiduna Abu Dharr (may Allah be pleased with him); he mentioned his own story and narrated the hadith: "Clean earth is water for the Muslim, even for ten years (if he does not find water). When he finds water, he should pour water over his body, for that is indeed better for him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 22