Hello,
The method you describe is called "touch dubbing", and used when you want to put very little dubbing on the thread to get a very thin body.
I use the traditional method , apply the dubbing on the thread by rolling it on with fingers, or a dubbing loop. From last week, as I received a Nor-vise, I apply it as demonstrated on the videos, dubbing on the spinning thread, see "part 7: dubbing":
http://fr.youtube.com/watch?v=39xvJCfd4Js
It makes quite a change!