Re: Can decongestants dry you out and cause more harm?
Decongestants are horrible creations, if you tend to have dry skin, asthma or tend towards dehydration. They'll turn a cold into pneumonia if you're not careful.
Until I was 43 I had more colds than anyone deserved because I had an undiagnosed allergy or intolerance to wheat, which is another story. Now I'm 46 and cold-free, but here's what I do now when I contract one every couple years.
Decongestants harden up your snot like cement, so it's hard to blow out your nose. Why would that help? I avoid decongestants -- they prevent your body from doing the natural thing - creating mucus to get rid of viruses or bacteria.
Drink as much water as you can reasonably stand. Drink it very warm because it goes down fast and warms you up. Tea is fine, but only if it's caffeine free.
Soak in the hottest, deepest bathtub available, as long as you can stand it.
Drink some more water.
Sleep as long as you can, undisturbed.
By doing this I create an artificial feaver to accelerate the demise of my cold.
Works for me. I completely knock out a cold in 24-48 hours. But then, I've had a LOT of practice.