We are due to change the head gaskit on my old work horse, a Peugeot 1.4 8v 206, its got quite a bit of mayonnaise in the header tank , so, I'm assuming there could be traces in the coolant pipes, when I say quite a bit of mayonnaise there is a bloody lot really. I want to flush the system but don't want something that is going to produce an avalanche of soap suds. Obviously the header tank can be removed and cleaned off the car. Any suggestions fella's?