In my experience, non-static meditation on this area helps develop more refined control of the apana-vayu. Because the apana-vayu controls the urogenital and anal/rectal functions, developing a high degree of control over these functions and their associated musculature will extend one’s control of this energy. When a parallel skill with the prana-vayu has been developed, these two energies can be united, and brought into the central channel. It is at this point that the effects on citta become pronounced with the grosser levels of conceptual cognition dissolving into the more fundamental cognizance underlying them.

Or at least that was my experience,
Ryan