What you’ve got should work in principle. Modern versions of Mac OS require an entitlement in your info.plist to allow your app to send Apple Events to other apps. This is an important security measure, even though it can be rather annoying to comply with.
The reason your ‘odoc’ Apple Event works is that the open document event isn’t filtered by the security system, while your custom “AEts” event is.
The solution is that you need to tell the OS you intend to use Apple Events by including a key/value pair in your application’s info.plist file. Check out this prior discussion: