I would suggest using pharmaceutical grade rubbing alcohol (95% or better)which you can get at many drug stores, since it will evaporate readily. You can actually use water, distilled would be best. What ever you use '''prior to cleaning the board remove the battery from the board and discharge the capacitors'''. Liquid will not hurt the board or components if there is no electricity present. Batteries and capacitors store electricity. After you clean it dry it with a hair dryer. '''Be sure, be comfortable, that all is dry''' prior to re-installing the battery and the power source.