How can continuous pouring or immersion of water suffice for ghusl, according to those who hold that rinsing the mouth and nose are pillars (rukns) in wudu and ghusl? And what is meant by continuous pouring of water, and what is the extent of the "brief moment" in which the wudu is considered valid when performed in sequence, knowing that the questioner follows the Hanbali madhhab in these matters?

The Shafi'is explain regarding the purification of one who has a minor ritual impurity, such as for ablution (wudu'), that if an impure person immerses himself in water with the intention of removing the impurity, his impurity is removed. This is because the water meets the limbs successively along with the intention. The soundest view among them is that it is valid without delay. As for the Hanbalis, they stipulate order (tartib), unless one immerses himself in flowing water, and four currents pass over him, which then suffices for ablution. However, if the water is stagnant, only the impurity of the face is removed. If he takes his face out, then his hands, then wipes his head, then exits the water while observing the order, it suffices according to the soundest view of the madhhab. Rinsing the mouth (madmada) and sniffing water into the nose (istisnhaq) are obligatory according to the Hanbalis.