meditation should help you with that. You have to just nothing about it (i know its harder than it sounds), but thats what you have to do. If you get the impulse to swallow just do it absently and keep going. The bigger problem is actual the fact that you are sitting there thinking "Dont swallow, dont swallow, come on man why cant i just sit still" which impedes your progress a lot more than actually swallowing.

Also try to focus on moving your brain away from your body if that makes sense. You become more and more detached from your body in the process. So focus on any weird sensations or sounds hear or focus on things inside of your head like thinking about what you will dream about. This will help detach you and accelerate the process, and it will also distract you from intrusive thoughts.