Many disposable medical devices tend to be of poorer quality, in addition to disposable things if they come from informal manufacturers but sterilization is not in place.
Oral appliances are generally required to be sterilized in sterilized bags with sterilization instructions and expiration dates on the bags. Sterilized water soaks are being phased out because some are not very reliable.
If you see instruments that are rubbed with alcohol or something like that, run away.