This results in lower temperatures, longer

 The thermal conductivity of Thermal Grizzly Kryonaut is 12.5 W/mK, while Arctic Silver 5 has a thermal conductivity of 8.9 W/mK.
Because of its unique high-density filling of micronized silver and increased thermally conductive ceramic particles, Arctic Silver 5 provides a new level of performance and stability. There are Arctic Silver resellers all over the world. The Arctic Silver 5 premium thermal compound is the gold standard in the industry. Arctic Silver 5 is intended to work with a wide range of bond lines connecting modern high-power CPUs to high-performance heatsinks or water-cooling systems. EFFECTS ARE SURPRISING – You may notice a drop in temperature after the first use of this thermal solution, which will reduce the loudness of your equipment and improve its comfort of use. THE MARKET'S NUMBER ONE – Many tests have confirmed that the most popular option meets the highest quality standards not only of standard computer users but also of ardent Overclocking enthusiasts.
The surfaces of CPUs and heatsinks have minute pits and valleys, no matter how perfectly flat they appear. These holes and valleys trap air, which is one of the worst heat conductors known to man, and this is where thermal pastes come in. Thermal paste is designed for excellent thermal conductivity and is used to fill all of those small pits and valleys to allow molecule-to-molecule thermal contact. This results in lower temperatures, longer component life, and no burned-out CPUs. If you don't have a heatsink and thermal paste installed, it only takes seconds to irreversibly damage or kill your CPU. Thermal pastes are available in a number of different quality levels.
I still have enough to finish all three, but my initial application on the CPU and GPU was the larger quantity that some people use for other pastes, but this paste heats up quickly and doesn't work well with too much. I've found that adding very little at a time and spreading until a paper thin coating forms on the surface of whatever you're glueing works best. Don't worry if your layer isn't perfect or even; the Heatsink will take care of it. Thermal Grizzly Kryonaut vs Arctic Silver 5
Others have used it after 6 years with no issues, but that was with a brand new tube. Before you begin, make sure the connection between the heat sink and the CPU is clean. If you notice that your CPU's temperature is rising after using your own 10-year-old tube, I recommend replacing it. In fact, I'd recommend getting a new tube anyway. This tube is small and compact, and it will suffice for a few applications.