Thermal paste is designed to conduct heat and transfer it from an IC to a heatsink.
Loctite is an adhesive designed to help hold bolts in place - including when heat makes the metal expand/contract.
These are not the same thing.
When it comes to thermal paste, almost anything is better than nothing at all (even toothepaste and peanut butter), but many materials have qualities that are bad for your computer. You don't want to use anything conductive or difficult to remove (peanut butter, adhesives). You also don't want to use anything that will dry out and stop working in a day or 2 (toothpaste). Most new Heatsinks will come with thermal paste, and the stock heatsink that comes with a CPU will have a thermal pad on it that will perform adequately, just not as well as a good thermal paste that has been properly applied.
I wouldn't recommend using anything but thermal paste unless it is an absolute emergency - and even then you should replace the alternative with thermal paste as soon as possible. Even if your only option is a very cheap or relatively low quality thermal paste. You should be able to find some at any computer store or Best Buy. There's also tons of options to order online. Walmart doesn't usually stock it as far as I know, but they might ship site-to store depending on where you are.
When applying thermal paste, remember to use the smallest amount that will still put a thin layer between the center of your CPU and the heat sink.