The chiller was new when I bought it never used in a salt water tank.
I opened the box which came from the importer.
This tank has 80% RO.
I was warned against tilting the chiller in the very beginning coz it damages the chiller.
I will try the vinegar method to clean the chiller internally.
But it seems I'm going to need a lot of vinegar solution.
As for dust and dirt I have no choice but to open the screws and suck the dust with a vaccum.
I've had 4 different chillers (tradewinds, current & 2 JBJ's) at various times prior to my break and the only one that ever needed a vinegar flush was one that was connected to a saltwater tank. If you are using 80% RO flushing is a waste IME and not needed.
Regarding the dust if you have compressed air that would work well, if not then use a slender paint brush to aid with getting the dust out.