The "hot wet towel in a paper cup" treatment is this: Put a paper or cloth towel in the bottoms of two paper coffee cups, then pour in just enough boiling water to thoroughly soak the towels. Immediately put the cups to your ears, keeping as tight a seal as possible. The steam that gets created will help to unblock your ears.
From personal experience, this can work. (Your mileage may, of course, vary.) However, I have also heard from health care professionals who say that this treatment also creates an incredibly fertile environment for very bad things to happen.
[This message has been edited by wideman (edited 11-02-2000).]