How to get rid of phlegm?

I have occasional bad breath which I am sure is because of the phlegm caught up in my throat. I just can't get it out! Salt water gargle , toungue scraping , nothing! can get it out.... I really need to get rid of it and the bad breath. Im using listerine but it jus gives few hrs of clean breath.Then Im not sure if my breath is bad or not.I brush, floss etc. So its defintly not my teeth... help!