Nakow! Don't use a vacuum cleaner when cleaning electronic components. Static electricity can build up in the dust particles traveling along the vacuum intake tube and run along those particles into your mobo. It gets worse if you're in a dry, airconditioned environment. Better to use a brush and ground yourself by touching the pc chassis every so often.
Use contact cleaner as much as possible when cleaning the ram 'fingers'. In a pinch, you can use a pencil eraser to clean the 'fingers'.