Kids with extremely snotty heads can be trained to clear their sinuses by teaching them to inflate “nose balloons”:
The balloon helps a kid put air pressure on their eustachian tubes from the pharynx, which opens them and helps keep the middle ear drained. Us grownups do the same thing easily by just closing our eyes, holding our noses and “pushing”, like on air trips or while driving in mountains or scuba diving. But try to explain that push to a little kid!
My daughter uses the balloon with great gusto mornings and nights, and often she comments on the wind she then hears blowing inside her ears. That’s when an obstructed tube opens and admits air into her middle ear.