Keeping your air-conditioning on removes any moisture and thus reduces fogging. Doesn’t have that much impact on economy anymore and most cars are set to have it on by default for this reason.
If anyone does smoke or vape in the car, just open the window a bit and direct your exhale towards it, the pressure of the moving air outside will drag it out.
If I seem a little strange, that's because I am.
Skoda Karoq SEL.