A lot of people get frustrated because in the detailed area of ships, its hard to get the grime out. Q-Tips are too big, and you cant just blast it with water because of decals. My solution: Buy a soft head BABY toothbrush at the drugstore. Its a normal tooth brush, with a little head. Its also very soft. Use a mixture of warm water and a mild soap, and try to keep as much water as possible away from the decals. This is especially useful on the Millennium Falcon.
Just scrub the ship gently in the dirty ares with the baby toothbrush and solution. This will make your ship look proud again.