How to clean heatsink & CPU?

[gsf600y]

Hi,
Currently got my stock cooler installed on Intel i7 4790K.
Working just fine, but have now had this delivered:

Unfortunately, looks like someone has had their grubby mits on it already, clear finger print on it Looks like the box has already been opened too. All OK though.

So, I've got some Isopropyl alcohol. Is that going to be fine to clean the heatsink with?
And can I also use it to clean the old thermal paste off the processor?

Lastly, do I use my 9 year old Artic Silver 5, or go with what came with the heatsink:

Any cleaning tips appreciated

Thanks

 

[gsf600y]

You may have to lap the base with 1000grit wet+dry.
its the oils from the skin that "etches" the marks onto the bare metals.

Seriously? Wow. "etches"?? Maybe I should get it sent back then. Rather annoying. Will they affect the thermal performance?

Isn't sandpaper just going to badly scratch the smooth finish?

 

[gsf600y]

I'd love someone to do a benchmark test with a heatsink with fingerprints and a heatsink without and compare the difference.

You need to get out more

I'm going to clean it, and live with the finger print. Some lucky guy at OcUK or the Alpenfohn has his finger living in my system for the next 10 years

Thanks for the advice chaps