Indicates an extreme level of wetness, not just slightly damp. The storm left the tents wringing wet; there wasn't a dry spot anywhere.
Pro Tip 2/3
Physical Action
Suggests that something is so wet, it could be wrung out by hand to release water. My socks were wringing wet after stepping in the puddle.
Pro Tip 3/3
Visual Imagery
Creates a strong image of how wet something is, helping listeners visualize the situation. She was caught in the rain and came in with her hair wringing wet.