Probably the worst possible materials to remove thermal compound tbh.
WD40 - a mixture lubricants and oil.
Pledge - wax
Alcohol - yup but it needs to be strong stuff.
Spit - quite possibly a mixture of all the above along with some fat aswell.
With the exeption of alcohol, all of the above will leave residue on your core/HS which will hinder heat transfer.
If you want it to look clean then use whatever cleaning stuff/fluid/spit!?! you have to hand. However, if you want it to really be clean then use IPA. Don't believe me?? Do your self a favour and clean a HS with specialised 'TIM' cleaner, it will look very clean (and is better than nail varnish etc). Then clean it again with some IPA, you will be surprised how much more crap IPA gets of a 'cleaned' HS.