I would just flush a few seconds after each shot while the PF drains, cleaned off the screen a treat.
Then once a week -
Drop the screen and gasket into very slightly soapy water, use the group brush while the screen is off, and then rinse and refit the screen/gasket.
Wash the water tank.
Backflush four 10 sec cycles with water.
Monthly -
Pulycaff backflush & cam lube. Soak PF/basket in Pulycaff
3-monthly -
Lubricate paddle and steam wand ball-joint.