Muhadith Nuri (may Allah have mercy on him) said narrating from Kafa'ami in his book "Baladul Ameen" that Imam Al-Mahdi (peace be on him) said:
Whoever writes this supplication in a new plate with Imam Al-Husein's soil (peace be on him) and later washed and drink it shall recover from his sickness.

بِسْمِ اﷲِ الرَّحْمٰنِ الرَّحِیْمِ

Bismillaahir-Rahmaanir-Raheem

In the name of Allah the Beneficent the Merciful.

بِسْمِ اللهِ دَوَاءٌ، وَالْحَمْدُ لِلّٰهِ شِفَاۤءٌ، وَلَاۤ اِلٰهَ اِلَّا اللهُ كِفَاۤءٌ، هُوَ الشَّافِيْ شِفَاۤءٌ، وَهُوَ الْكَافِيْ كِفَاۤءٌ، اَذْهِبِ الْبَاْسَ بِرَبِّ النَّاسِ، شِفَاۤءٌ لَايُغَادِرُهُ سُقْمٌ، وَصَلَّى اللهُ عَلٰى مُحَمَّدٍ وَاٰلِهِ النُّجَبَاۤءِ۔

Bismillah dawaa’un, walhamdu lillahi shifaa’un, wala ilaha illa Allahu kifaa’un, huwa ash-shaafi’u shifaa’un, wa huwa al-kaafii kifaa’un, adhhib al-ba’sa birabb an-naas, shifaa’un laa yughadiruhu suqmun, wa sallallahu ‘ala Muhammad wa aalihi an-nujabaa’.

By the name of Allah which is medication, praise be to Allah which is cure and there is no god except Allah, the Sufficient, He is the Cure of the cures, He is the adequate of all Sufficient, suffering should quit with the permission of the Lord of men, and grant medication that is not accompany with illness and may Your blessing be on Muhammad and on his superior families.!