as a chronic ear problem sufferer...here's the only way i know of to clear blocked Eustachian tubes. high dose guaifenesin. i couldn't frickin believe after all the years of problems that no ENT told me this. i went to a specialist for adults with chronic otis media and he just casually said, "yeah, lets clear that crap out of your ears first. this will do it." worked like a charm!
guaifenesin is a potent "thinner" of mucous. the dose for clearing ears is quite high, so you need a prescription. do it in combination with an anti inflammatory agent...like flonase + ibuprofen. the cause many times is exacerbated by leftover adenoid tissue blocking drainage.
another one that's a pain for pilots...never blow your nose while holding one nostril to try to clear it. you may actually push dirty mucous into your ear.
hope it helps someone!
cheers