I wouldnt go vaping water to be honest ... at least not tap water. But to be serious ... PG does irritate and dry up your throat when vaped ... water wouldnt i dont think. So ... stuff that in your pipe and smoke it!
I wouldn't vape tap water either, that stuff is hazardous to your health, evian perhaps, but never tap water. I actually was being a bit cheeky in my comparison, I've read studies on PG going back to the 1930's when they claimed it prevented rats from catching the flu. I prefer PG to VG because IMHYEO, it gives a better throat hit and I don't trust VG, to many variables. I do know a few people who are very sensitive to PG, and have had reactions including everything from intestinal issues to swollen glands and of course the sore throat/dry throat issues. I seem to be able to tolerate it quite well. I will say, that I had a pretty bad reaction to a bottle of what I'm assuming was either straight VG or primarily VG that I bought from our local cig shop. Clearly an import, but I was out of juice and desperate. Never again.