Up here the "pinch one nostril and blow out of the other" is known as the Gateshead Hanky. Perfectly acceptable sporting behaviour, not so acceptable if walking the dog/school run. Just make sure no one is in range.
Edit: make sure no one sees you doing it, if you live on Gosforth. Oh God, the shame...."Tarquin saw Justin's daddy expelling mucus from his nose......"