My dad has Parkinson's and has very poor-quality sleep. He also has had anti-snoring surgery in the past, and chronic post-nasal drip (which I also seem to have). This article raises questions in my mind as to whether any of these are related.

Also interesting is this: "researchers were able to successfully modulate cervical lymphatics using phenylephrine (which activates α1-adrenergic receptors, causing smooth-muscle contraction)"

Phenylephrine is the so-called decongestant that has finally been called out for being a fraud in oral medications (and I can tell you from painful, painful experience that it is indeed a fraud). I was surprised to see that it allegedly accomplishes something in this particular application.

https://www.cnbc.com/2023/09/12/decongestant-phenylephrine-i...