I am a common object used by everyone, typically about 8 inches long. One end has soft bristles, and the other has a small hole.
I rest most of the day but am always ready for action. When in use, I move back and forth within a warm, moist cavity.
After my task is complete, a white, foamy residue remains, and I return to my resting place. I'm usually cleaned afterward.
What am I?
Surprise! I am your very own... toothbrush! What were you thinking?