Well, FWIW, I would say you are on the right track - make sure everything is in tip-top condition. BG44K can be run without changing the oil - in fact, if you need to change the oil after running something through the fuel tank, I'd say you have larger issues than the cleanliness of the injectors anyway!

As for the plugs, just pull them and check the condition. If the electrodes are worn, or they are fouled, I would certainly replace them.