[Raion]

I don't recommend using cotton swabs to clean anything on the system boards. In the past I used old toothbrushes that I cleaned really well of human residue.

Nowadays I actually have nylon cleaning brushes that I can literally dip in rubbing alcohol and then run through almost any type of nook and cranny. I often will follow that up with a rinse if a board is dirty, followed by a drying session up in my water heater closet, then a hair dryer over everything to force all the remaining water out and then an alcohol bath from a parts washer to displace any water and then I put it back in the cupboard until it dries for about 24 hours.

Overkill perhaps but considering I don't have ultrasonic cleaners or anything this is the best way I've actually been able to clean off crap.