Asklemmy

Snoring is produced by soft tissues vibrating when they flop where they shouldn't (i.e., blocking airway).

It is thus indicative of reduced airflow, which can result in negative health outcomes - including yes, brain damage. The full condition is called obstructive sleep apnoea (OSA), but there are other conditions like upper airway resistive syndrome.

From the pictures I see online, it looks like an OTC mandibular advancement splint (MAS). MAS are used for management of OSA, but only per the prescription of a sleep physician, who needs the results from a sleep study as well as an examination of the patient.

Not all OSA sufferers will tolerate let alone benefit from a MAS. There are drawbacks and side effects with a MAS that may not be discussed with all patients, let alone purchasers of an OTC product.