I use to work at a shop and we sandblasted (glass beaded) all engine parts including many pans. I would be more concerned about areas you can't get to good and that is why I was hesitant on the driveshaft and axel housing without a clear pic in my mind.
Colin, yes with water. I blow them off right away however. When you are blowing off parts there are two stages, one for the liquid to come off, and a second you can see the metal actually dry out and lighten. The water is vital to get the dust off, especially on parts like the pan that will enclose bearings. I will almost always paint shortly thereafter to prevent rust from forming. Initially however it will be fine until it becomes damp again.
