Not at all convinced with the Krown Shayne, which you used to think was brilliant, so surprised to hear you mentioning Aquasteel.
Also cannot believe that after a jet wash with water in every nook, cranny and void, that Krown then sprayed on the wet surface gets into, and displaces all that aforementioned water.
Flaking paint or rust, just creates a new patch for the rust to keep going regardless.
I used to be a firm believer in Aquasteel but after the last lot no more. It was not working as previously, (new bottle from the manufacturers), and before going too far, gave up and dumped the lot. I'm guessing that along with many other different manufacturers of goods, it has been messed with for a bigger profit.
Just a stiff brush and degreaser for prep, wow !
We all have our own beliefs, so whatever works best for anyone.