Sayyiduna Laqueet Ibn Sabirah رضى الله تعالى عنه narrates: I asked: Oh Messenger of Allah (peace be upon him). Tell me about Wudoo’ ? He صلى الله تعالى عليه وسلم said: Perform Wudoo’ وضوء thoroughly, pass water between the fingers and put water up the nostrils properly, except that you are fasting. (Abu Dawood/Tirmizi)
While fasting, water should not be put up into the nostrils, nor gurgle intensely, because if water goes inside, then the fast will be nullified.