Flushing the engine and radiator

[Barrieb]

Having replaced the waterpump that was leaking oil into the cooling system, I have tried using the usual "safe" engine flush, running it up to full temp etc, but has not shifted the milky goo in the bottom of the pipes so I can only assume same In the radiator engine etc.

I had heard (not sure if it was on here) of someone just adding detergent, then flushing and that worked fine.

Does anyone have a better idea or advice on what risks this may have?

Thanks

[Tuco]

I've heard of people using regular laundry detergent in cars, but I'v never done it myself.

[drut]

Used "washing soda" such as http://www.walmart.com/ip/Arm-Hammer-Super-Washing-Soda-Detergent-Booster-Household-Cleaner-55-oz/19407690 on contaminated car cooling systems,works really well on removing oil/grease then follow up with good flush with straight water.