In order to be discreet, I would probably use a vaporizer in that situation, most of the time, and also use sprays and/or an air purification machine to clean up whatever odors remain.

I currently use Lysol Neutra Air, but the best I've ever used was Ozium spray - very little is needed, I don't know how it works today, but when it was manufactured in highly pressurized aeorsol cans it lasted for a long time........ it's very good at getting rid of smoke and eliminates, rather than just covers up, odors. It's recommended for dorm rooms.