The Quick Select tool in Photoshop is very fast. You mostly only need to swipe a little bit of the background and it will figure out where all the edges are. You can use Actions to create a macro to turn the selection into an alpha channel, save, then close.
When you shoot your object, try to make the background as plain as possible, and a color that is very different. Something like a neon green poster board will make masking easy. You don't need to mask the turntable, only the parts of the image that don't turn with the object.
When masking, make sure that feathering and anti-aliasing are turned off. You want the edges to be as sharp as possible. You don't want photoscan trying to work with pixels that have been altered in any way.