I've been practicing it for about several years and I can do 10 to 12 pull-ups with proper form.
It took me a couple of years to get to this level. I'm very proud of myself.
Now, my interest is going to my son. I really wanted him to practice it as well.
Fortunnately I was able to convince him to start it. As he is a super beginner, I suggested to him that he use a pull-up band.
This material allowed him to complete pull-ups with less strength. Right now, he has very fun doing this exercise.