Another old yet reliable solution for combatting persistent dry cough is by using lemon, particularly in combination with honey. The high levels of Vitamin C included in these fruits (88% of your daily recommended value in 100 grams) will encourage rapid healing while rebuilding your immune system. All you have to do is squeeze a fresh lemon into a glass of warm water and add honey to taste, repeating the remedy every time your cough starts acting up again. This solution works so well because lemon relieves congestion, while honey soothes your aching throat.
Remember what we said earlier about home remedies for persistent dry cough from your childhood? This is definitely another one that has stood the test of time. Personally speaking, when I was young my chronic bronchitis led me to infinite fits of dry coughing, my mother would brew up some onion tea that she almost had to force me to drink down. I was equally surprised every time to see how amazing I felt afterwards. As a tip, try holding your nose before you can feel the smell of onion and add some honey to help wash it down.