Wow, smooth like a mirror. Maybe you can help us by doing some lapping services here

Won't the sand papers slip off when lapping with the use of dishwashing liquid?

I see, thanks for clarifying. This applies to lapping a processor's IHS as well?

As long as you doesn't expose the copper surface to the air often by removing the heatsink frequently.

Use Intel TAT, it's way more accurate as it reads the temp from the processor's core. Less the hassles of removing your heatsink while endangering your prolly from being barbecued.