For 120, your AP tank and the stabilizer step, just put 300 ml of solution in the tank, turn it on it's side and gently roll it continuously through the entire time.

Or if you have a roller processor of some sort (Beseler, Cibachrome, Unicolour, JOBO etc.) let it do the work.

You can do this with any of the solutions. It is though a bit of a challenge to maintain the temperature of the developer to within the necessary tight tolerances.