Thermal paste has vital importance, even if many people do not realize how useful it is. On the web, you can find many alternatives to the thermal paste. This article has test comments on several alternatives, which many of are edible snacks.
The article mentions: Cocoa and hazelnut spreads, butter, Ketchup, mustard, American cheese, Yellow cheese, Banana, Cheese spread
Remember that those hand-made experimental methods will delete the CPU warranty.