Sand blasting engine parts

[p.hammar]

Hi everyone. Some time ago I posted questions about my engine renovation and particularly about sand blasting engine parts. It's going well and I am blasting away at all parts that are not related to sensitive systems, like fuel.
Now I have come to the gearbox, which is severly corroded after having been submerged in salt water. Se picture. I can take it off from the bell housing that it is attached to now, but then what? Putting it in the blaster cabinet seems stupid, as there are bearings between the gearbox and the shaft coupling that comes out of it, and I cant protect that from flying sand. What method would you use to clear this from all the horrible white and grey stuff?