I feel dumb for not knowing what the product I want is, but I'm looking for something to paint on machine screw threads to make them a little harder to turn. I don't want to permanently fix the thread position as with a traditional thread locker, but rather make the turning a little harder. An example of what I'm thinking of is a yellow substance painted on the machine screw under Kreg bench clamps. Makes the screw a little tougher to loosen or tighten.

The application is the leveling screws in my router plate. They turn very easily (a little too easily) and the vibration from routing eventually loosens them. Something on the threads would help keep them in position.