The way to propel the mind towards nibbana is to keep on seeing anicca with a sense of unsatisfactoriness
(rather than merely watching anicca and oh let me go have a cup of tea after that
). When this is applies to all the 6 sense doors the world is caught-enveloped in your practice. The mind then rejects-pushes away (not develop aversion) the world little by litte. Then at one point it pushes away all sensory phenomena (read conditioned phenomena)- this is nibbana. This is true emptiness. The path is through developing revulsion leading to dispassion leading to cessation. It is not easy, but it the only way to get there.
So the important thing to know about emptiness is that it is the byproduct of the practice, rather than a practice. THe mind knows how to reach it- you dont need to teach it- infact I suspect all the contortions of views around emptiness might contaminate the process. Emptiness as an object might take you to the sphere of emptiness and not nibbana.