Even though I have the opposite problem and hypersaliviate in the oral cavity, I still have problems with swallowing and mucus in my throat. I have found that Papaya juice really helps.(without getting to technical, the enzymes in the fruit break down mucus, as does pineapple juice but I find papaya works better) if it's to thick mix in a little bit of soda water or sparkling mineral water. It's not always so easy to find, some health shops will stock it but if you are lucky enough to live by an Indian Deli or stockist you will get it no problem.
I know there are other solutions too as no doubt someone will post and suggest but if you can swallow and take in some sort of nutrition the vitiman C content is quite good too.