Started 2 years ago with an OTC boil and bute, sleep quality is night and day (no pun intended),l. In fact it annoys me greatly if for whatever reason I don't sleep with it because I know I'll be yawning, nodding off, and generally low energy all day. Highly recommend it at least as a low cost experiment (mine was $70), no issues so far with bite or jaw soreness.
Can you show us how does it look like? Is it similar to the ones for fighting bruxism?
Mine is from VitalSleep.com (promise I'm not astroturfing, you can find 50 similar products)