I have to agree with Malcolm's comment about this approach to hollowing being useful to those who are "watching the clock". I use the technique only when I need to remove a lot of material quickly. For that purpose, it works very well. But it has its drawbacks and if I had never learned it I can't say that I'd be any less effective at hollowing.
It's simply a technique and, contrary to some commentary on the practice, there's really no "trick" to it. Learning to use this method for removing material requires using a very small section of the cutting edge, consistently, throughout the cut. There is no margin for error and, if the turner looses concentration for an instant, it's all over.
My suggestion would be, if you're not involved in production work where you've got to meet specific quotas, use the traditional methods for hollowing with the bowl gouge and forget about this one.