I used to wash the traces of Janaba (semen) from the clothes of the Prophet ﷺ and he used to go for prayers while traces of water were still on it (water spots were still visible). (Using translation from Bukhārī 229)  

كُنْتُ «أَغْسِلُ الْجَنَابَةَ مِنْ ثَوْبِ النَّبِيِّ ﷺ فَيَخْرُجُ إِلَى الصَّلَاةِ وَإِنَّ بُقَعَ الْمَاءِ لَفِي ثَوْبِهِ»