Get ready for the Pull-Slap (Part 2 - The Slap)

Let's see how you did in your description... here's mine.

1) Your lips are over 4 holes (standard size)
2) Your tongue starts off the harmonica
3) Start to breath... as your air ramps up place your tongue on the lower three holes, leaving the rightmost hole open to sound. The end result is a chord that leads to a single note (tongue off... tongue on...). Saying "HALL" is helpful... the "HA" being the chord and the "LL" representing the tongue on the harmonica.
4) Make sure the single note is clean when done. Rhythmically speaking, the chord is the pickup and the single note that follows is the target.

Give this a try... really FEEL, HEAR and KNOW what's going on with this technique...