My doctor wrote a prescription for an in-home suction machine to help clear my mouth of the excessive phlegm/saliva.  My insurance paid for it and had it delivered right to my house and then picked it back up when I was finished with it.  I used it for several months.  I would also keep a glass of Ginger Ale or 7-UP on my nightstand to help clean the suction straw.  After I would suction my mouth, I would then dip the end of the suction straw into the glass and the carbonation would help flush the phlegm through the tube.  I would highly recommend everyone to get a suction machine!