If vinegar completely removes filth from a garment, Abu Hanifah and Abu Yusuf consider the garment purifiable by it. Yet vinegar is not valid for wudu because it is not unrestricted water.
The distinction lies in removing actual filth versus meeting the prescribed medium for ritual purification.
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Types of Impurity and Methods of Purification
If vinegar completely removes filth from a garment, Abu Hanifah and Abu Yusuf consider the garment purifiable by it. Yet vinegar is not valid for wudu because it is not unrestricted water.
The distinction lies in removing actual filth versus meeting the prescribed medium for ritual purification.