Works great!  Far better than just alcohol alone.
I was skeptical, but figured I'd give it a try.  Turns out it works FAR better than alcohol, although I'm pretty sure the ingredients of the first bottle are just alcohol and d-limonene (orange oil), which makes sense because d-limonene is a fantastic and safe cleaner.  With the first bottle, you just put a few drops on the surface, wait about 30 seconds, and wipe the old thermal paste off.  This stuff eats the thermal paste away so there's really no scrubbing.  I do this twice just to make sure everything is off, but that's just me.  It's somewhat expensive, but it does work really well, although next time I need to clean a heatsink and CPU I'm going to mix some d-limonene in with some alcohol and see if it works the same.  If so, I'll just start making my own concoction.
Rating: 5 stars