Ultrasonic cleaner size: 10L vs 6L

[tooki]

The frequently observed "white residue" probably requires a saponifier (alkaline) remover in water.

Were you secretly thinking of dish soap when you typed this? If so, whisper it in my ear and I'll add it to my solution next time.

As I already told you: dish soap is NOT a saponifier! Stop fixating on dish liquid, no matter what you've seen "everyone" do.

Automatic dishwasher detergent is likely alkaline enough to do the job, but at the expense of possibly being too corrosive. Aqueous, saponifier-based flux removers/PCB cleaners are designed to include corrosion inhibiters and generally be suited for electronics.

[tooki]

As noted above,yes, hand soap.  And the brass brush has to be very soft, like camel hair almost.

For cleaning watches perhaps. But the question is about cleaning PCBs, and for that, hand soap or dish liquid is pointless -- at least if flux is to be removed.

[CaptainBucko]

FYI Attached is the datasheet and SDS of ChemTools Kleanium Printed Circuit Board & Electronic Parts Cleaning Solution which I have been using with success in my UltraSonic cleaner.