Okay, this one is weird but true: a dry throat is a snoring throat. If he breathes through his mouth all night, the tissues get sticky and vibrate like a loose guitar string. A humidifier in the bedroom can add moisture to the air, softening those vibrations.
Even better? A quick saline nasal spray or a steamy shower before bed. If his nose is stuffy, his mouth takes over, and that’s when the chainsaw starts. Think of it as pre-gaming the silence.