how best to clean/treat corrosion inside 200tdi water jackets??help needed

Hello again,
Okay so today im refurbing my 200tdi used cylinder head.
Mine had corroded on the 3 triangles on the head.
But i have also taken off welch plug/core plugs and can see that theres years of crud inside the engine block. Ie rust and what looks like sand at the the bottom.
The engine is in the car and i am wondering the best way to clean the inside out in situ.
(Dnt want to take it out again as i have hust put it back in after changing clutch,front timing case, belts seals etc)
Ideally id like to use some sort of heavy duty rust remover (have read to use clr,evaporust)
then something to neutralise/seal the metal after??? Any ideas anyone??
Thanks Paul

A power flush to remove years of crud and any loose particals. Theres nothing u can do now about the rust now, the correct antifreeze should have been used from day one, but refilling with antifreeze now at the 50-50 strength will stop it getting worse and may even help neutralise it some what.

Sorry for late reply..
Yh that looks like the plan.i dont want to do more damage with acids
New/used Head ended up needing valve seats recut so whilst that and valves are being done its time to stop putting the block off an clean it up.
Cheers

FranksDiscovery said:

Sorry for late reply..
Yh that looks like the plan.i dont want to do more damage with acids
New/used Head ended up needing valve seats recut so whilst that and valves are being done its time to stop putting the block off an clean it up.
Cheers

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Maby Evans waterless coolant could help, not cheap, but reviews seem good