Many scholars are of the view that purification of najaasah can only be done with water, just as purification from hadath [wudoo’ and ghusl] can only be done with water.
The view of Imam Abu Haneefah (may Allaah have mercy on him) is that it is acceptable to purify najaasah with any pure liquid that can remove it. This view was also favoured by Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him). It says in al-Ikhtiyaaraat al-Fiqhiyyah (p. 23):
Najaasah may be purified with any pure liquid that will remove it, such as vinegar and the like. This was narrated in one report from Ahmad, and was favoured by Ibn ‘Aqeel, and it is the view of the Hanafis. End quote.
The second view is more likely to be correct.
Shaykh Muhammad Saalih al-‘Uthaymeen (may Allaah have mercy on him) was asked:
Can najaasah be purified with something other than water? Does the steam with which coats are dry cleaned purify them?
Removing impurity is not an act of worship that is done for its own sake, rather the aim of removing impurity is to remove a dirty and impure substance, so whatever removes the impurity and its traces, that thing is purifying for it, whether it is done with water or benzene or anything else. So long as it removes the impure substance, by whatever means, then it is regarded as purifying it. Indeed, according to the more correct view which was favoured by Shaykh al-Islam Ibn Taymiyah, if it is removed by means of sunlight and wind, then the place is purified, because it is as I said: the issue here is the impure substance, and wherever the impure substance is found, that place is regarded as impure, and when it is removed the place goes back to its original state, i.e., it becomes pure again. Everything that removes the impure substance and its traces – except some colour (stain) that cannot be removed, and may be forgiven – is something that purifies it.
Based on that, we say that if the steam with which coasts are dry-cleaned removes the impurity, then it is something that purifies. End quote.
Majmoo’ Fataawa Ibn ‘Uthaymeen (4/86)
And Allaah knows best.