To play the same note rapidly (e.g. 16th notes) it is useful to use the index finger of your right hand to play the string with a flicking motion (inwards and outwards as shown in the diagram below).
Use only the tip of your finger, similar to a pick.
In Lick 22 use only the index finger of your right hand.
As a variation play the following lick with the middle finger.
You can also use your thumb to play this technique as in Lick 24.