flux cleaner spray. If you use as intended, you get very little out of a can. Easy to use a whole can on a standard size equipment PCB (i.e. 10x8 inches).
Yes, it’s easy to do that, but entirely unnecessary. You don’t use it by drenching the board and rinsing over and over, you use small amounts through wipes. Think of the way you clean windows with Windex. Sponge bath, not shower.
I used to clean boards with lots of liquid, but I realized that careful scrubbing with the wipe actually works better (less chance of redepositing flux elsewhere on the board), and uses far less solvent.
if you have alot of parts its mad annoying to try to do that. Like a board that you solder a bunch of stuff too in the middle of equipment with tons of solder wires and bolts and brackets and other shit.
Like I replaced a bunch of composite resistors scattered around a PCB that had like 50 wires, a few brackets, caps, etc. Trying to go between all that with a brush is really bad. But I was able to tilt it, spray a whole can of flux remover in there, and it came out OK after 10 min of work rather then like an hour with probobly lifted traces, replaced wires (if you resolder the creep too much and they will be too tight with 1 more strip).. if you use the brush on the can with a flood, it does work pretty good, but only do it if you know that you just don't have the patience to make it brush accessible.
And its the only good way to get stuff like flux that is under transistor plastic/ceramic spacers for instance, where you solder the transistor with the loose spacer on top of it. When you add flux some comes out the top, unless you want to do a submersion, you won't get that out without a good flow from experience.
And no idea about stuff like QFP soldered with rosin flux... or BGA, I imagine you also need to flood that good. But at that point you pretty much need a ultrasonic I think.. how to be confident there is no flux under a BGA ?