Bill2 is confusing buildup of wax in the ear and otitic barotrauma which affects the eustasian tubes. Read
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Wax forms in the outer ear which is separated in healthy ears from the middle ear by the tympanic membrane.
The barotrauma affects both the inner ear and the sinuses and sudafed may help relieve the inflamation of the eustasian tubes. The better solution however is DO NOT FLY. If you do fly with inflamed eustasian tubes and manage to clear them thus relieving pressure on the tympanic membrane and open up the sinus cavity you will relieve the pain in the short term but risk allowing infection in to the sinuses and the middle ear. This might need anti-biotics to clear up and could affect your flying for days or even weeks.
What wax might do in the CLIMB is to allow a build up of pressure in the outer ear while the pressure in the inner ear drops with the drop in air pressure. In the descent the outer ear will have eventually equalised with the lower pressure but there will be a natural increase in pressure in the middle ear. This is the reverse process from the blocked eustasian tubes. While it can be painful it is less likely to result in a barotrauma. You will still suffer from cloth ears though.
Another less frequent condition occurs if you have been breathing pure oxygen. The air in the inner ear is displaced by oxygen which is more easily absorbed in to the blood stream. After flight the oxygen continues to be absorbed thus reducing the pressure and creating pain in the ear. This condition may be relieved by drinking beer, talking in the bar, or other oral exercises.