I am PG sensitive and my cough vastly improved once I went to VG, distilled water, and then PEG500 which is the BOMB when it comes to replacing PG for flavor. I can handle about 10% PG then it's all pins and needles in my throat from there on out. I did not develop PG sensitivity right away, and I also didn't get a rash or traditional allergy sx, ,my system does not like it. PEG400 requires the willingness to DIY, and I'd also recommend (as I always do) researching it a bit. I didn't find anything alarming so I went ahead and started using it, and I remain not alarmed at all. But it is one viable option, I find flavors smoother and crisper than VG/DW alone.
As far as coughing, well, dual use (for me anyway) always involved a bit of coughing daily and I coughed for some time until like, I realized, "this won't stop unless I stop dual use." My throat was torn up when I got here, so switching to salts also helped me immensely and I DIY with them at 18 mg/ml at first although I seem to do fine with freebase too nowadays.
The reason that smoking doesn't make you cough is due to some big tobacco modifications that BT did, including adding something called "humectants" to the tobacco and they moisten it and help the smoke sliiiiiddde down your throat. (They're probably in all likelihood seriously bad for you too) but that's what does it.
Some people are very sensitive to nicotine levels and vapor. You do have some options.. You can do the M to N inhale/exhale, where you inhale the vape into your mouth and exhale through your nose, avoiding the vape entirely when it comes to your lungs. You might be surprised at how efficiently the mucosal membranes and sinuses absorb nic, there are plenty of successful vapers doing that and you could up your nic too if you wanted. I find that type of inhale to be ultimately unsatisfying and that's my biggest issue with it, but it is something you could try and adjust to while you are dual using to adjust to vaping and higher nic and do that until you are ready to drop smoking and it's more of a "habit."
I was surprised at how much snus helped me, and not just for job related issues where I KNOW it is going to help me not feel like I want to constantly vape. I can use a 20 mg/ml piece of snus and be comfortable for a couple hours, for me it's place it and kind of forget it. It's really helpful at not letting my nic levels drop below what I consider "safe" during long periods which are then triggers for me to smoke. It's also (I presume) got more of the nicotine alkaloids in it, meaning (I presume) that it helps me to not smoke period. It was a life saver when I first started out trying to end this dual use thing and I'm sure I will always vape for the hand to mouth thing, but heck, say you buy Generals Snus (the name of the manufacturer from Sweden here in the US and they only make 8 mg pieces and the flavor isn't fantastic, I prefer the white, if I had to pick one) and seriously, your first piece of snus will NOT taste good, probably. They make white, mint and wintergreen and PUSH through that first few pieces and you may be surprised at how effective it is. I was. If it hadn't been for
@hittman , and the "what is under your lip, nose, etc. right now thread, I think my dual use might have continued much longer and ALSO work would have been... a challenge.
it seriously may be worth investigating it with an open mind. You can vape ON TOP of it if you need/want to, and I have done so at times, but I kind of liken it to the patch-- you can wear one to keep your nic levels sort of on a more even keel especially if you have to take long breaks between vaping. A nurse practitioner suggested that to me one time, and I was like, "UM but there are all these warnings about doing that," and she just laughed and said, "Yeah, but you are a 3 ppd smoker I sincerely doubt you are going to override your nicotine tolerance."
Although I wasn't successful that time around, well, she was factually correct. And snus is even more EFFECTIVE than the patch (and cheaper probably) because it's got more WTA action, I would seriously recommend trying it.
Really keeping my nic levels high enough (however I do it) is probably key (for me). I say I started out at 18 mg/ml but I'm going to bet it was higher than that, because I was using Aroma's wholesale nic and that was either 36 or 24 mg wholesale and I would put a tiny squirt in the tank, and it was probably enough to boost my nic some and I believe two things happened to me a) I had higher nic levels AND WTA levels to start and b) when I switched to Umbavapes and then Ohm's WTA (and I think they're decent but not epic) but when I entered stressful situations and really couldn't afford Aroma anymore well, I just upped my WTA levels but was using 12 mg WTA and really didn't stop to consider what that was doing to my nic levels honestly, and probably my WTA levels because I think Ohms/Umbavapes WTA is SERVICABLE but nothing like Aroma's and someone sent me a wholesale bottle of Aroma's and I was indeed astonished at its ability to help me not smoke even during my most daunting periods and etc.
So, do anything and EVERYTHING you can think of, honestly, it's worth it. It is SO MUCH worth it. Good luck,
Anna