If they were able to figure out a way to develop it why not eanyone else?
If that is your desire you can try it and see. The better you are able to clarify your goal the better the chances of success. E.g. in what situations would you like to use humor? How would you like to act differently?
Will the paraliminals help? I'd say better than nothing and certainly something to get started with while waiting for something better to come along.
Write down your goal and then try the paraliminal. Then record the small successes that you notice. Remember it builds progressively so it might be subtle.