^^ I agree ... a small spot blaster works great for cleaning up those hard to reach areas.
I use one made by
Zendex along with their recovery system.
The recovery system includes a few different rubber tips (including one that fits into inside corners) and helps quite a bit with keeping the blast media from going everywhere. It's not 100% perfect though ... there are still some spots where the rubber tips won't fit and you have to blast without it.