Rocking horse scenes??

In the first scene where the rocking horse comes to life, he sticks his tongue out and has a milky white fluid all over his tongue and mouth. Later, when Vicki/Mary Lou is rocking on it, she has her fingers in his mouth and again there's the white fluid. It's pretty nasty.

Is that supposed to be, umm, "baby batter"? It sure does look like it. If so, what on earth is the significance??