I wash my board with a spritz of high pressured air. Gets all the dry dirt and dust off. Best way to clean the grip tape too. Just go to a gas station and use the air compressors that are used for car tires.
@Future-Motion could you weigh in on why the above charger from @DocBlock (Aspect Solar Energy Bar 225) stopped charging after version 3034 was released? Since that is the case do you have a recommendation for a portable battery?