For me the saliva problem, itching or even moving is a sign that I am too focused on my physical body.

When I am focused on a visualization and totally forget about my physical body I never experience saliva problems, itches or that I am moving.

Although since saliva, itching and moving doesn't affect the WILD attempt at all it is actually not even something that you need to worry about.

The worrying creates more trouble than the worry itself.
Good luck!