With no reason to spit, you can go about your daily routine without any interruptions for things like a little extra saliva.
Though there isnt much research on how vaping affects your hair, one study found that chemicals in e-cigarettes do affect the genes related to epithelial cell growth, possibly even more than traditional cigarettes (Martin, 2016)
Change your routine around that revolves around smoking like to stop smoking when in the car, drinking coffee, stay away from friends who smoke, and go to places where smoking is not allowed like non-smoking restaurants, libraries, museums, and theaters
Check the destination countrys customs regulations to ensure compliance
What tests are available to diagnose or rule out gastric cancer