There are several training benefits of going right down to actual Vmc which I can think of.
Hmmm, I can't think of any. In fact I can think of some very good reasons why you wouldn't go down to actual Vmc particularly on some twins.
I have to agree with Big Pistons Forever. This is the technique I have used sucessfully for many years.
It's a bit like stalling, where we are not teaching students how to stall the aircraft but teach them how to apply the correct recovery technique, loss of control at Vmca is the same.