Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.
Vodka. Works a treat.

I use cotton buds...give good scrub till no more black on bud...takes a good while to clean proper...and dont use too much as best not to soak cpu in it 
No you want a TIM cleaner. I use Akasa TIM clean which is citrus based (smells lovely)