I absolutely think there is a connection. If this person were to get up to 20 minutes, I think they might see a really clearing of these passages. Suggest they try 30 minutes in as long as they can go between rounds (like 8 3 minutes pulls or something like that). They might feel like they are coughing up a lung, but eventually I believe they will feel great relief during the day. Then again in the evening.
I have allergies, always have. I was not one to spit of anything during the day, and now, first thing in the morning, I relieve myself of quite a bit of phlegm. I can breathe much easier all day too.
I'd say this therapy is amazing for that condition.