Another thing to remember is that the cleaner the pro's use is likely a lot more potent than fuel injector cleaner, since it doesn't have to be combusted in an engine. I have been involved in cleaning fuel injectors for gas turbines and we used an ultrasonic tank, a lye-based cleaner that is heated and the lye should also be pumped through the injector. Once cleaned and rinsed, it needs to be tested for flow, spray angle, voids and streaks.
This is one job I'd recommend leaving to those that have the right equipment.

Kåre