Best Block, Head & Radiator Flush ?

Does anyone know of a very good over the counter auto store cast iron engine block,/cylinder head waterjacket, and radiator cleaner & flush product ?

Years ago I used to use a two part Dupont Heavy Duty Radiator Flush & Engine block & Head cleaner flush powder product that came in a two section silver canister.
It was the best coolng system flush & block / head & radiator water jacket cleaner I have ever used.

The Part A cleaner powder was some sort of acid.
You warmed the engine up and put the prt "A" acid powder product in the coolng system and ran it for for about fifteen min.
Then drained the product and added the smaller pr "B" container , which I believe was basically baking soda, to neutralize the part "A" acid.

This Dupont product would clean-out all sorts of heavy scale & rust and do a fantastic cleaning job indeed !

I have not seen this Dupont Heavy Duty Radiator & engine flush in any auto stores for many years.

What Auto Store over the counter product, that you can buy today, have you successfully used as a good cast iron block/head & radiator cleaner cooling system flush?