Hey Al, you can try Mucinex. It never did work for me but it is known to help others.
If you can keep a humidifier by you it will help but not a total fix.
I dealt with that for many months and I still after 8 1/2 years suffer from dry mouth and thick phlegm.
This is what I found works best for me:
First thing in the morning, after I eat each meal and sometimes in between; run as hot as possible tap water, swish and spit, swish and swallow small amount and hack it out and repeat until clear. Water pic my teeth and gums, brush well with quality paste, rinse well and brush with Sensodyne and prescription fluoride paste, spit but don’t rinse.
I imagine you’re experiencing dry mouth and the above regimen along with drinking lots of water will help. No medication or mouthwash has helped me with dry mouth.
Some people recover quickly and others like myself never do so don’t give up and continue to fight the good fight!

MOJO