I’m a retired doctor GP casualty and sports medicine one. I also trained inWestern medical acupuncture primarily for pain conditions in athletes. I could use this at the Paralympics to good effect.
I decided to self acupuncture re phlegm build up. Although I still sipped hot drink at night to thin phlegm amazed I got through 7 hrs sleep when I’d only been able to achieve 2-3hrs. It may be a fluke as not everything responds to it.
I will try it a couple more times this week and record its results.
Be very careful don’t take yourself off to anyone who isn’t qualified, in UK you should be a member of BMAS with a dipmedAc diploma at least. I’ll keep you posted if it fails or succeeds again.🤞

I feel certain the phlegm comes from my throat. The phlegm,itself has a different consistency and even taste than nasal mucus. I happened to see my doctor when having a particularly bad day. After examining my throat with a lighted tube that went up my nose and down into my throat, he agreed that it was coming from my throat.
I think the symptoms from post Covid are just different from the usual conditions of the throat and nose from allergies, strep, colds,etc..

Did you get tested for silent reflux (LPR) already? Sounds like that could be it since mucus in your throat is one of the main symptoms. You could suffer from it without having the typical heartburn that comes with normal acid reflux.