Invalidating EOSharedEditingContext through DirectAction

Hi,
I've been trying to force a refresh of a sharedEC using Direct  
Action, but I just can't find a way to access the application's  
SharedEC through my DirectAction class.
I tried:

but got an issue about static context.

So here's my situation:
-a back office application
-a front office application
-a framework

I need to "force" an update of the front office when the back office  
is updating/adding/removing an object.
Always the same "data-freshness vs power-consumption" thing:)

What's new today is that I now have my application (at least the  
front office) linked against the Wonder frameworks, so maybe I have  
some "other" ways than just trying to force a refresh of the entire  
front office sharedEC...

I can also linked the back office to Wonder if there's a nice way  
through it:) (not sure I have to do something specific for the  
framework)

I didn't find anything for now, anyone with a pointer?

Thanks a lot

Xavier

PS: There may also be a way through the use of notification or  
something like this, to allow the back office and front office to  
listen to each other, but I'm really not confident about that, so if  
it's the way I should go, thanks for a little more than just a pointer;)