I had a friend over to work on my computer and when he opened the case, everything was very dirty. (Hasn't been cleaned in many years). He tried to use a can of air to blow the dirt, but it only removed the very top layer of dust. He pulled out the cards and motherboard, removed the chips on the motherboard and then went over to the sink and started to rinse off the boards under tap water. He then immediately took a blow dryer and dried the boards. The boards appeared brand new. He put everything back together and it worked fine. Is this an acceptable way to clean cards. The cards that he cleaned were the motherboard, video card, soundblaster card, SCSI card, modem, and network card. When I asked him about it, he said that the important thing is to quickly dry the card, otherwise rust will set in.