Yes for dirty cars and even moderately dirty ones
The thing to do though is to stand alongside the car and spray the water across the paint, not at it
99% of the population normally spray straight at it. You are pushing the dirt into the paint with that method
Side panels - use a horizontal pattern
Rest - vertical pattern
Really dirty cars should have the excess
grime removed with the pressure gun at about 50% pressure, then full pressure
Accummulator is my inspiration. Because of him I adopted a 4 bucket, 6 mitt method and that number will only go up, maybe 6 buckets
I hate swirls and marring