I say, and with God's success: It is required for him to introduce water inside the qolfah - the skin of the male that is placed on the glans, which is cut from the boy's member - correctly so that the washing is valid. Refer to: Al-Tabeen 1: 14, Gharar Al-Ahkam 1: 17, Ramz Al-Haqaiq 1: 10, Sharh Al-Waqaya p. 92, and Majma' Al-Anhar 1: 21, and God knows best.