Is the Hadith of Aisha, "None of us had more than one garment in which she would menstruate. If she saw any trace of menstrual blood on it, she would do this with her saliva," so she rubbed or scraped it with her nail, evidence that saliva purifies like water, and have any scholars said that?

The majority of scholars stipulate the use of pure water for removing impurity, whereas the Hanafis permit its removal with any pure liquid that can dislodge the impurity. They cite a hadith (definition) that might be interpreted as referring to the dissolution of blood traces with saliva, followed by washing with water. The view of the majority is supported by another hadith that explicitly mentions the use of water for washing menstrual blood. Al-Bayhaqi interpreted this hadith as referring to a small amount of blood that is excused. This issue is a matter of scholarly disagreement, and the opinion of the majority is more precautionary.