Anti-snoring mouthguards! I was diagnosed with sleep apnea and didn't think I could tolerate a cpap, so I found a local dentist office that has a side business called their "silent sleep center". They make mouthguards to stop snoring and sleep apnea. Mine works GREAT and is ultra-portable, perfect for the RV.
It looks a lot like a sports mouthguard, custom fit to your teeth, with bands along the sides to hold your jaw forward. It's adjusted by using different bands. Was expensive but I have good insurance and they didn't balk at all.
Works so well that my wife just got a lower-end model to help with her snoring (no sleep apnea). Was about $500 out-of-pocket, but worth it. I no longer need ear plugs and she's getting a better night's sleep too.