The one I'm specifically interested in is Wheat Bread. I've searched all kinds of ways and can't seem to find Behr LRV values.
The general outline of this therapy can be found here: Best natural cough treatment. This is the way how you can stop coughing for good. An additional factor to stop coughing naturally is to use Earthing for grounding the human body to get Earth's electrons to reduce inflammation.
Get plenty of rest. Drink plenty of fluids to prevent dehydration. Take care of your cough if it is making it hard for you to rest. A cough is one way your body gets rid of the infection. And you should not try to stop your coughing unless it is severe enough to make breathing difficult, cause vomiting, or prevent rest.