Yes, there are masses of folks out there who do use them. I don't, but know several who do, even RNs and other medical workers.
My son is a Respiratory Therapist, and tells me lots of people use them but don't really advertise it.
Have you considered making these for sale at craft fairs? Or even as a personal little money maker? You could use many different fabrics and colors for it, but remember that they do have to be color permanent and sterile/washable.