Ic diamond doesnt stain a standard cpu heat spreader, the stain that liquid ultra/pro leaves can be cleaned of with a good metal polish cleaning solution. Application wise, ic diamond is different from liquid pro/ultra, and yes it's safer. With diamond, you put a small rice grain size amount of paste on the cpu. Then place the cooler on top. With liquid pro/ultra, you use a tiny amount of the paste, then spread it out from the centre of the cpu's ihs with a very small brush. And no need to apologise, your english is fine.