I use this method too on my two girl workers. They are both shedding at the moment and I get LOADS out.
You have to keep taking the hair off the comb as it quickly builds up.
I much prefer this method to a furminator, groomit, coat king etc.
I find that with other methods they work but the new hair grows at funny angles
I just use a cheap wide toothed comb (purchased as a set at Poundland
) with a thick rubber band interlaced in the prongs.
It just takes the undercoat out and leaves the shiny top coat.