Heat pipes sort of do that naturally without any active "spraying". They contain a fluid that phase changes and carries heat away. Closed loop water coolers have the active flow of water you want for maximum effect. I don't think your idea would be an improvement on that.

That's essentially what vapor chamber coolers are. It's a sealed unit where the working fluid evaporates on the CPU end, absorbing a ton of heat, and then condenses on the other side, before going back to do the cycle again. Because the heat of vaporization is so large, these can move a lot more heat than ordinary heat sinks.