Have a hiatial hernia thanks to coughing really badly from a bacterial infection last year (clean your humidifiers regularly people.) It flares up off and on and I treat that by going to the chiropractor who's treatment makes an immediate difference.
This time around, I got a bad cold. Though I seemed to be remaining functional by gargling cayenne pepper water, and a few other things, my coughing was starting to scare me because I didn't want my hiatial hernia to worsen (it's a near constant pressure on your diaphragm, either making you feel falsely hungry, or nauseated like you don't want to eat.)
A few of the things I tried here helped (cayenne pepper for sore throat) but the vicks, for example, worked only for a couple of nights. I tried the thyme tea and that worked out very well. Brewed up a bunch and drank it over two days and nights. My cough is now very rare and seems to just be about expelling phlegm, rather than an irritated throat that feels itchy but not sore.
As a side note, something that may or may not be related is that I think the thyme tea made my period show up 4 days early, similar to how parsley tea does the same thing. It might not be related but it is something that I will keep in mind.
My 79 year old Mother had an upper respiratory infection. She could not shake the cough. I had recently read an article that said steep 1 teaspoon of your kitchen variety thyme in a cup of hot water, as you would a teabag, and sip. She tried it and it worked. Encouraged, I told my friend who has the start of COPD about it, she tried it and is amazed also. The article stated it relaxes the bronchials. Yet another alternative.