I do it all the time. I do a hose free wash every couple of times I drive the car when it's accumulated road dust. But I will say I don't use this method if the car has been driven in the rain because too much grit sticks to the finish without a good hose blast to knock it loose. I use Chemical Guys Eco Hose Free Wash. It only takes about 1 oz in a bucket of water. Makes the water super soft. It doesn't streak or leave a film like car soap. I soak about 6 or 7 microfibers in the bucket. While they soak I use compressed air to blow what dirt/dust I can off the car. Then I take a spray bottle filled with water and a 1/2 oz of Eco Wash and spray a panel down to prelube. Then I grab a microfiber from the bucket, wring it and slowly drag a microfiber in one direction and flip the towel as needed. Once the car is dry I wipe down the finish with CG V07 spray sealant and buff to a shine. I have not run into a problem with scratching the surface whatsoever. And trust me, I'm super anal with my black car. Always comes out amazing.