In the video on the webpage at 0:14 the patient is using the device only for inhaling, not for exhaling. I tried breathing through my fist and it worked really

In the video on the webpage at 0:14 the patient is using the device only for inhaling, not for exhaling. I tried breathing through my fist and it worked really well. Since I am not interested in another device that I have to clean and carry with me on travels I will try the fist method in the next weeks.