I bought a cheap keyboard at a yard sale. It must have sat in someone's garage or basement for years as it is unbelievably dusty. Even the sides of the keys show dust when you depress the adjacent ones. Should I try to take the keys off to fully dust them, or just wipe the sides of each key?
I would take it apart the best you can and then spray it all down with one of those cans of compressed air. Wiping down something like this after years of collecting dust won't do much good I'm afraid.