What is the method for sniffing water into the nose (istishāq) and expelling it (istinthār) during ablution for a fasting person, and does it differ in Ramadan compared to other times?

"Istinshaaq" (sniffing water into the nose) is the act of drawing water into the nose by breathing to cleanse it. "Istinthar" (expelling water from the nose) is the act of expelling water from the nose after it has entered it due to istinshaaq. A fasting person should not exaggerate in istinshaaq for fear of water entering their throat.