No matter what you use to clean fuel injection stuff once it is dried out it needs to be at least dipped in diesel fuel so it won't rust and to lube it before assembly.

When I did this at work the disassembled parts went into carburetor cleaner, they were hosed of with water then dunked in solvent then blow dry with an air gun with special attention to the small passages. Once dry they went into a pan of diesel fuel.
During assembly I blew the excess diesel fuel off and assembled them and tested.

In the shop we only used the ultrasonic tank on Injector Nozzles when a hole was plugged and other methods to unclog the hole did not work. Indirect Injection Nozzles never went into the ultrasonic tank because the carburetor clearer took care of the carbon.

At Home it is a different story don't normally have solvent and never used carburetor cleaner but once at home; but I have compressed air. So I use the ultrasonic tank.

__________________
84 300D, 82 Volvo 244Gl Diesel