Dr. Rif`at Fawzi, former professor of Shari`ah at Cairo Univ. , states: “If a male had madhi on his underwear, he should either wash it or sprinkle water over at least the part of clothes touched by madhi. So, when he is not at home for example, it is sufficient to sprinkle water over the area wherever fluid appears. You should also make istinjaa’ (cleaning the private parts) and make wudu’ (ablution) before observing Prayer.”

Explaining the Shari`ah-based ruling on madhi and how to deal with it, the late Sheikh Sayyed Sabiq states in his well-known book, Fiqh As-Sunnah:
“Madhi is a white sticky fluid that flows from the sexual organs because of thinking about sexual intercourse or foreplay, and so on. The person is usually not aware of when exactly it is secreted. It comes from both the male and the female sexual organs, although the amount from the latter is usually more than the former. Scholars agree that it is impure. If it gets on the body, it is obligatory to wash it off. If it gets on the clothes, it suffices to sprinkle the area with water, as it is very hard to be completely protected from this impurity, especially for the young, single person.
`Ali (may Allah be pleased with him) said: “I used to excrete madhi, so I asked a man to ask the Messenger of Allah (peace and blessings be upon him) about it. I was shy to do so because of my position with respect to his daughter (`Ali was the Prophet’s son-in-law). He (peace and blessings be upon him) said, ‘Make ablution and wash your penis.’” (Reported by Al-Bukhari)
Sahl Ibn Hunayf said, “I used to suffer from excessive amounts of madhi. I used to make lots of ghusl because of it. So, I mentioned this to the Messenger of Allah (peace and blessings be upon him) and he said, ‘It is sufficient to take a handful of water and sprinkle it over your clothes wherever the fluid appears.’” (Reported by Abu Dawud)”