An enthusiast over at the ComputerBase forums has demonstrated that common household items like ketchup, cheese, potato, toothpaste, skin cream, and copper tape among others can substitute for thermal paste in case of an urgent need. The comparison showed the Arctic MX-4 to be the most effective in preventing thermal throttling of a 30 W AMD Radeon R7 240 GPU, but ketchup and toothpaste come across as decent substitutes as well.