A friend (Li Zhi) brought attention to me about this during a subway ride. I've just looked into it.
Blowing ears by holding the nose may help alleviate ear clog when changing altitudes/air pressures, but it is not a good idea to do that for the following reasons:
- Causes infection from the throat to enter ears. (Some site suggested that it is ok to do this unless when the throat has infection/sick)
- Causes damage to the ear drums if blown too hard.
The suggested solutions are just yawning or swallowing.