I'm on mestinon, but don't have excess saliva. Mestinon helps me have 'some' saliva, at least during the day. Extremely dry mouth is a symptom of Lems.

My problem is more the 'handling' of whatever's in my mouth be it food, liquids or saliva. Sometimes things just don't work right.
When eating solid food, I can get to about the third bite, then muscles in my throat and under my tongue start aching and just stop working, but the same thing can happen with just one swallow of liquid.
I can take a swallow of something and it may or may not go down. Usually goes about halfway down my esophagus , then starts reversing when I'm having problems.
Sometimes everything works fine.
I've been looking for a solution for this for a long time now. I do have an electric bed now, so I crank it up when I take pills at night.