Thermal paste
Thermal paste
I don't suggest using toothpaste as a replacement for thermal paste. It doesn't transfer heat as efficiently as proper thermal compound or a thermal pad such as IC Graphite. You can find quality thermal paste or a thermal pad for less than $10, but avoid substituting toothpaste for thermal compound.
India could be in a tough spot right now, but I'm confident you can find the Arctic MX-4 elsewhere. Check Ebay for options.