Raising CanExecuteChanged

Hi

I have a question, concerning best pratice of wiring ICommand interfaces, their CanExecuteChanged event and the "RelayCommand" implementation(s) with ViewModels property change events.
In the common implementation of RelayCommand.CanExecuteChanged the event delegates to CommandManager.RequerySuggested, which results in very reliable and accurate notifications as long the changes are invoked through whatever kind of user / UI interactions:

        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }

However if there are changes from the Model to the VM that have an effect on the CanExecute conditions of an ICommand, this implementation of CanExecuteChanged will of course not do anything, and the event will no fire. The net effect that a Button may still be disabled, although all condtionjs for having it enabled are met.
If we want the controls, that bind to an command to be updated and to get enabled or disabled, we have to manually fire the event, so expose sth like

public void RaiseCanExecuteChanged()
{
    CommandManager.InvalidateRequerySuggested();
}

and also listen to the relevant changes of the model objects and call the RaiseCanExecuteChanged method
on each relevant prop change (or whatever kind of event).
This can get a very tedious and bulky task, if the business logic is complex.

So my question is: Is there a more elegant a/o effective way to get the ICommand updated when there are data changes that the CommandManager can not realize? I know thatsome people simply use a trigger, which effectively solves the problem, but is kind of "dirty" to my point of view.
But in the end there seem to be only two alternatives: either use a trigger or do the wiring manually
Is there a better way, some auto magic?

Thx
Chris