Likely won't do much.
Hie thee to the local swimming pool, read a little about the Valsalva manuver, and practice it whilst swimming to progressively deeper depths.
It works both ways, that is, you can hold your nose and sniff too.
If you can't clear your ears once you're able to develop enough pressure in your nasopharnyx to make little bubbles come out your nasolacrimal ducts, you need to be on Afrin and Flonase.