Have you tried a new technique called "licking"
Remove the heatsink, scrape the grease off using a razorblade, and do not touch the cpu copper top with your finger. After removing the paste with a soft cloth, add a rice sized drop of arctic silver to the heatsink, rub it into the heatsink, then wipe off with a cloth. Lick the cpu with your tongue, do not put much saliva on the cpu.