The first attempt was too weak and I didn't notice enough improvement via physical inspection to warrant reconnecting everything just to have the same results prior.
That said I broke down and ordered the heavy duty cleaner in the gallon bucket with the little plastic bucket that sits inside the "bath". I put the injectors in and let them soak from Wednesday through yesterday afternoon (4-ish days).
I removed the injectors from the bath last night and they look better than they ever have before, probably since they were new. In the spirit of the holiday weekend, I included a festive element to the photos.