Water does the work if it sticks around. Moisture is one the firefighter's best friend. Moisture that stays, plays!
Let's look at the definitions: http://en.wikipedia.org/wiki/Moisture
Moisture refers to the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in various commercial products. Moisture also refers to the amount of water vapor present in the air."
Performance Comparison of Classified Wetting Agents Shawn Oke
Take a few minutes and review this information on the value of Conditioning / Painting tactic to reduce the risk of flashover while accessing a concealed fire.
Enhance Water Streams in the access...
The below short video is a demonstration of how the enhanced water stream vapor moment has a positive effect on the flaming even when the stream itself doesn't hit the flames directly. Fire decay is the goal.