Hadith
حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرِ بْنِ زِيَادٍ، حَدَّثَنَا شَرِيكٌ، عَنْ قَيْسِ بْنِ وَهْبٍ، عَنْ رَجُلٍ، مِنْ بَنِي سُوَاءَةَ بْنِ عَامِرٍ عَنْ عَائِشَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ كَانَ يَغْسِلُ رَأْسَهُ بِالْخِطْمِيِّ وَهُوَ جُنُبٌ يَجْتَزِئُ بِذَلِكَ وَلاَ يَصُبُّ عَلَيْهِ الْمَاءَ .
Aishah said:The Messenger of Allah (May peace be upon him) used to wash his head with marsh-mallow while he was sexually defiled. It was sufficient for him and he did not pour water upon it
Da'if · Al-Albani
Sunan Abi Dawud 256 ·Book 1, Hadith 256·Also available on sunnah.com·