Been using the volcano with a bag for @11 years. I make pretty big bags and go through 3 per session with 3-4 sessions per day and have never gotten an infection. When I was new to this I used to cough also as the volcano produces a very dry vapor. To combat this I always have water to drink/sip to replenish moisture and as someone else pointed out take smaller draws off the bag. At this point I no longer cough or even notice the dryness. I would also turn your temp down to 375° ish instead of 400° as that will also help a little.I appreciate peeps taking the time to offer advice.
Back maybe 4 or 5 years ago I made some ISO wash as was vaping this and got a respiratory infection. I am pretty sure the ISO wasn't purged all the way, but it sucked.
I was concerned and wondering if anyone has had the same experience with dry herb vaping. Hope not.