I got a problem with that mit he was using in the video.
The blueish looking elastic cuff on the mit was occasionally making contact with the paint, which will cause scratches. Also, the lambs wool could catch and hold dirt which will scratch the paint.
I use this microfiber cleaning applicator to clean the car because it doesn't have any abrasive materials, and I can clearly see any dirt on the applicator.
Blue Perl Microfiber Applicators
I continuously use a spray nozzle to clean the applicator as I am washing the car. Only one bucket of soap needed.