Is the prayer invalidated by repeatedly making sounds from the nose to clear mucus during prayer, and what is the ruling on swallowing this mucus through the throat as a result?

The sound of mucus being drawn in during prayer does not invalidate it. If the worshiper swallows mucus through the throat without it reaching the mouth, their prayer is valid. Clearing the throat (tanaḥnuḥ) and expelling phlegm (tanakhkhum), if done out of necessity, is permissible. If a person swallows phlegm that has descended into their throat, it does not invalidate their fast or their prayer, even if they were able to expel it, as long as it had not reached the "hawāt" (meaning, it had not come out of the mouth into the throat).