I've was recently learned a few good details about the Shaolin sweep from half guard/z-guard. This sweep goes by many names such as roll over sweep (Caio Terra), the Frazzatto etc. This is the sweep that Bruno Frazzatto hit on Cobrinha in the 2008 mundials. Many people see this as something advanced, but in my opinion this a basic sweep that we all should master. It is also good as a movement drill.
The new details about the grips and the movement of the arm while going for the sweep are all explained in this video. Just have the patience to watch and absorb..