Sayyiduna Sahl bin Hunayf (may Allah be pleased with him) says: I used to suffer great difficulty because of madhi (pre-seminal fluid), and I used to take a ritual bath (ghusl) often because of it. So I asked the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Ablution alone is sufficient for you for it." Yazid added: I said: O Messenger of Allah! What if it gets on my garment? He (peace and blessings be upon him) said: "A palmful of water is enough for you, which you sprinkle on your garment where you think it has touched."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5573