You absolutely do not need anything but cotton balls. This crap about using solvents is heresy I say! The chemical composition of thermal paste is such that it does not leave residue when "dry wiped" but as soon as you introduce moisture, things change. You'll have to actually clean it off once you do that, instead of just dry wiping it off easily and just as effectively. I want to shoot the person who introduced the "Windex" approach (might as well call it that) nonsense to impressionable people...
Anyways, IF you want to go this route, why not just buy a product supposedly sold for this purpose? The risk you take if you go out and buy your own chemicals is that many solvents have additives that might either leave a film of oil on the die or chemically react with the thermal paste. You might not see it, but chemically it might all stay on the die. There's a very good reason why even fingerprints (read: oils from your fingers) are bad on the die/heatsink plate - and yet you want to use solvents that could potentially cover the entire surface with residue?
If you're dead set on this route, then get a hold of some Zeiss Pre-Moistened Lens Cloths wipes and use that. Eye glass lens cleaners are usually your best bet because they're completely oil free, and the cloth are lint-free also.
No, I would not use any alcohol that has a dye introduced. The objective, if a solvent is used, is that upon evaperation it leaves NO residue.
Grain or wood alcohol is fine, the LOWER the water content the better. PS Booze is NOT an exceptable alternative.
Most pharmacies sell 90% alcohol, the 10% being distilled water. Myself, I use 100%.
On lens wipes,verify that it has NO silicones, Many eyeglass wipes use a silicone as a lubricant and to fill in vey small scratches.