I have an old laptop (1999) that's just lying around. It needs new thermal paste and I have nowhere to buy it. I read some stuff about using toothpaste and vaseline as thermal paste. Since silver is a great conductor of heat/electricity, I'm going to ground a new quarter into dust and mix it into the toothpaste/vaseline mix. I want to know if this is safe. I'll be trying it anyway, so I'll update when I do it.
That's a bad idea, but everyone has to learn their life lessons, a new quarter has copper in it and copper conducts electricity very well, toothpaste dries out, and vaseline heated turns to oil.
You can buy Artic Silver 5 from Radio Shack, silicone compound from a Best Buy, but if you are determined to take this type route, you can use High Temperature Water Proof Axle Grease, it at least will stay where you put it and not dry out.
But no matter where you are on this planet you can order the proper Thermal Compound.