Smoke alarms typically won't go off unless you blow the vapor directly at it. Try taking a short puff, hold your breath for around 10 seconds and see what comes out. It's not much. When I have to stealth vape, that's what I do. If I hold my breath for a little longer, no vapor comes out at all. As for the scent, I'm going to be asking a friend of mine to mix up a batch of 12 mg juice with just a touch of sweet but no flavor to see if that will work.