If an object subscribes to something, this is a 2 sided action. Once on the object that it subscribes to and once on itself.
As your objects needs to update the string it must known to which "string offerer" it is subscribed and this can be used to unsubscribe it before freegadget-ing
As your objects needs to update the string it must known to which "string offerer" it is subscribed and this can be used to unsubscribe it before freegadget-ing