I guess I feel good that I am only 5 days post TX and I am able to sleep 4-5 hours between spits and wet pillows. And I am speaking OK, I guess its really is location dependent and exactly what part of what muscles and tissues were effeceted. Here is what helps me sleep:

Sitting upright when it gets bad
Keeping a cup bedside to spit in so I don't have to get up.
Not drinking or eating (stimulating my saliva) just before bedtime (few hours).
Finishing brushing and oral care atleast 1/2 hr before bedtime helsp things too, lets my mouth calm down before I lay down...

Rinsing with cranberry/soda water has helped the most to loosen up my mouth and throat from the mucus and sores, etc...it strips the slime out and lets things breath a lot. it stings but its worth it for sure.

-dw