Okay, so I stopped by Walmart and picked up some Humco USP glycerin. Mixed up a batch for 18mg:
9 drops Platinum Ice 54mg
7 drops flavor
5 drops PG
9 drops VG
Seems to work fine. Interestingly, I've noticed that I don't get as thirsty with the VG in the mix. With enough vapor, that Apple Pie is really good...