Bellflower root juice good for preventing rhinitis

I have a sensitive nose and weak bronchial tubes, so even when I catch a cold, I usually get a runny nose or cough. During seasonal changes, I experience severe nasal congestion, and in summer, when I turn on the air conditioner, my nose gets blocked, making it hard to breathe. Of course, I also visit an ENT specialist, but as a long-term solution, I have been taking doraji (balloon flower root) juice. Medicine can't be taken for a long time, and it's not a definitive cure either, so I have my own secret method of consistently taking it, which has helped reduce my cough.