Good summary. To add to what you've said, Sudafed (as an example brand name) opens your eustachian tubes which are passages from your inner ear to your throat. If you think you might be getting an ear infection, Sudafed increases draining and potentially helps prevent a worse infection. As mentioned, it helps air equalize to the atmosphere via these tubes. If you make a yawning motion now and hear your ears crackle, that's the air moving through your eustachian tubes. You'll notice that crackling decrease when an ear infection may be imminent. I tried the useless alternative and discovered on my own that it was, indeed, useless. And it was quite expensive, with great marketing on the box.