You can totally get away without the liquid with some creative lighting sound and gags such as platforms with meat/parts and such attached to it that would push out the other side. You can also have some of it hand operated by the actor throwing parts or entrails and such into the air as they are lowered in if you you turn it vertical like GEP's old Ghoul Grinder animation. (http://www.gepproductions.com/props/ghoul_grinder.html). Plus, if you really wanted the liquid effects it would probably work more efficiently and not be that hard to do and reset with a setup like this.
You could really get away without using any motors at at all...if an actor is involved...make them part of the operation of the unit!
Just some thoughts.
Mike "Pogo" Hach