stumbled on this and its great to know, i used to smoke marb lights for years then went on to marb menthol which my dad also smokes, been trying to get him into vaping started 50/50 mix and no matter what he could not get a good lung hit he would always cough.. came across a rip trippers YT vid he talked about a couple older guys who he tried to get into gaping and no matter what they always coughed could not get a good lung hit so he mentioned an all vg juice which i tried but still coughed.. saw it wasn't true vg the flavoring and nic was pg base so it was 80vg 20 pg.. so i went and tried a different vendor upnvape that uses base vg for flavor and nic and is 100% vg and still violently coughs when taking a less than normal hit (think he's gotten a little wary of the violent coughing which is understandable.. so the 100vg didn't do it and i kept researching something anything different and came across virgin vapors its a 100vg juice base also carry a virgin line which does not use alcohol in the extraction process ill quote them "The Absolute line is also created using third party certified organic flavors. However, these flavors are extracted using a multi-stage, patented process that does not require alcohol. All of the Absolute e-liquid flavors are alcohol free. In addition, the flavors themselves are highly concentrated and very expensive to distill. "
seems to be that the alcohol had some effect on him and so glad i came across a juice that he can vape without coughing, a lot of researching just glad i found something he can vape, although he still smokes hopefully it will continue to be cut down more and more.. sorry for the long winded post just figured maybe could be of help is someone has had a similar experience