Answered by Ustadh Tabraze Azam
Question: If there is still a small amount of impurity on the clothing despite using a jug of water, is it considered clean?
Answer: Wa alaikum assalam wa rahmatullahi wa barakatuh,
I pray that you are well, insha’Allah.
If the filth is visible, one would need to remove the body of it. Any traces that are difficult to remove thereafter would be excused. [Shurunbulali, Maraqi al-Falah; `Ala al-Din `Abidin, al-Hadiyya al-`Ala’iyya]
Hence, if one removes the main body of the filth, washes the area with water (with some rubbing to clean), and some traces of the filth still remain, one can assume purity.
And Allah alone gives success.
Checked & Approved by Faraz Rabbani