Soap & Foam
What you want is long chained soaps,not just any soap.
For instance Fels Naptha does a good job in reducing foam, however Savon de Marseille, or Lux Flakes can cause more suds.
Strange, but find soaps do a better job of foam control with liquid detergents than some powders. In all cases a tiny bit of carept cleaning foam suppressent (which is mainly silicone based), knocks down foam better and keeps it down, versus soap.
L.