Actually, I CAN see that dual using could be irritating to the throat, I found it to be so when I dual used (to be fair, once I got to vaping exclusively, I found out I was PG sensitive, so I also moved to max VG liquids (though I still MTL, it works out fine). But, when I started vaping I got hoarse, SO HOARSE for about the first 5 days. I had to liberally up my liquid intake, and do things like chamomile tea with lemon and honey, but it passed in time.... It was just an adjustment phase, I think, but dual using I coughed MORE than just smoking and it really didn't seem to agree with my system. Why that might be, I have no idea.... I think my respiratory system was just getting shot, period, more from the smoking than anything else.
With that said, there are things you can do, if nic is harsh on your throat you could lower nicotine, or try nic salts which have almost no throat hit at all (they also are more bioavailable so Juul makers claim, so more closely mimic a "cigarette" in more rapid satisfaction, though to be honest, I mainly bought them for the LACK of throat hit), which I don't so much care for in vaping.
What helped me most during transition was using SPARING amounts of WTA juice, then slowly phasing it out. Whole Tobacco Alkaloid juice contains some of the same alkaloids as tobacco, so while you would still be detoxing from tar (itself an MAOI), it did actually help me transition completely. They aren't cheap, though some places will give you wonderful deals on the stuff, but they did do what I needed-- provide a step down phase where I was still getting the MAOI satisfaction, while detoxing off tar, and at a much lower level than smoking, but enough to help. I know this doesn't work for everyone, but it might be worth a shot. My detox wasn't exactly pretty even WITH WTA, but at least I wasn't ready to chew through steel by 4 p.m. Then I sloooowly phased them out, but I keep a tank with some in it for stressful situations. It was much easier to stop WTAs once I had some vaping time under my belt.
Finally, you don't HAVE to stop dual using right away, I'd experiment with your VG/PG to see if you find a liquid mix that is more to your taste. It's kind of a catch 22 right now, if you want to vape more and smoke less, but are finding your vape hard to use due to dual using. But, I'd count every cigarette NOT smoked as a win, and start setting up a system of rewards for yourself, so that as you decrease your cigarettes, you increase your motivation to continue. It could be something as simple as an inexpensive item you've wanted, but held off on purchasing, new hobbies, whatever. I went back to knitting and crafting as a hand activity to keep me busy during times I can't vape, also took up the guitar once my voice returned and I could sing again, that type of thing. I literally did NOT know how to reward myself at first, as I was so used to "rewarding" myself with a cigarette. I had to sit down and make a list, LOL.
With all that said, you're going to have to try different things until you hit on the correct combination to quit. Motivation is a part of that, but only you are going to be able to give it to yourself. Again, sitting down and writing out the pros and cons of vaping versus smoking might be of help here, but I think step number ONE is finding a vape you can tolerate, as it's very hard to quit if vaping isn't working right. With that said, for a long time I told myself while dual using that I "had" to keep smoking since vaping wasn't "working," and this time around I decided to flip it and MAKE vaping work for me, no matter what, as I was being given an extended look forward into my COPD future by having pneumonia pretty much for 18 months straight (a lot of that time, I wasn't even AWARE I had pneumonia, thought it was allergies, etc.) but the treatments for that and how I felt convinced me that smoking wasn't worth it.
Good luck! Vaping *isn't* like some of the quit devices that only seem to work once (zyban, I am talking to you) if you've quit before, you can do so again. Provided you believe you can, I believe you can, but that probably isn't much help to you.
Anna
Anna