So apparently you press B and C alternately? I think i get one or two out every once and a while but I cannot do that consistently. Any other tips?

You just need to practice it more. Eventually, you'll be able to do it more consistently. I'm working on it too but I'm definitely better at doing it now after practicing. It is very uncomfortable to do though.

I don't think there's any trick to it. You just need to be fast and practice it