wipe thinly on the applicator from the can, apply thinly on the surface. you'll have an easier time buffing it off. search for wowa wax to make it even easier.

i have never used a duster. i believe less touch, less swirls. microtex has a gray, waffle weave drying towel costs 600 Php. assuming your car is clean except for the dust that settled, two of those and blasting the dust off with water won't be problem anymore. flap the towel on the car, avoid rubbing if possible. that's my minimum cleaning method. usually the minimum is to foam the car, pressure wash, dry which is short of a car wash w/ soapy chenille.