All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.
The correct method of seeking treatment through the names of Allaah The Almighty is by including them in one's supplication, such as, "O Allaah, curer of diseases, cure me." or the like. Another way is to read the names of Allaah The Almighty on water and drink it or wash oneself with it, or on oil and rub it on the body.
Some people believe that every name has special functions and related secrets and claim that there is a spiritual servant for each name serving the person who mentions it regularly, or that every disease has its unique name which cures it. All these claims are considered speaking about Allaah The Almighty without knowledge because no single authentic text from the Quran or Sunnah of the Prophet, sallallaahu ‘alayhi wa sallam, supports these claims.
Allaah Knows best.