Does salt water purify the impurity of gum bleeding, or must the water be pure?

If gum bleeding occurs frequently and is excused due to hardship, it is not obligatory to wash it away. It is sufficient to spit it out and overlook its traces. Swallowing it does not invalidate the fast for those who are commonly afflicted by it. Purifying blood with water mixed with salt is considered sufficient by some scholars, and this is the madhhab of Abu Hanifa and one narration among the Hanbalis, and Ibn Taymiyyah preferred it.