Ishi sticks are used as pressure flakers.
There is a type of reduction that uses an antler attached to a stick and is struck by another antler,stick or rock which is an indirect percussion. I think Marty Reuter has a youtube video on a horizontal stick using indirect percussion.
Hope this is what you are asking. There are some posts in the ABO Knapping section on indirect also. If you havent tried using antler punches then you may want to give it a try also.