Yes, it's true. You can see this for yourself if you turn the can upside down while you press down the button on the top. Then, it will spray liquid solvent out, which will immediately vaporize, and therefore rapidly chill anything it's on.

In my former life debugging signal timing issues on circuit boards I used to use this trick (using those "gas duster" cans upside down) to chill individual components to try to find out where the problem was.