I learned that to clear my ears on the way down vs filling the oxygen mask up with snots (sic), I had to remove my mask and pinch my nose very hard with two hands to get the ear canal to open. Using the holes in the O2 mask could provide the necessary closure pressure. The ear pain can be quite bad if you don’t clear your ears. On one occasion, I had to call for a halt to the descent until I got my ears cleared. It was the flight surgeon who told me I had a complex ear canal … I didn’t know that prior.