In the past when I fried turkeys, I had mixed results injecting various liquids into the bird. With a good soak in the brine would I still need to inject?
Does adding corn starch to the rub actually make the skin more crispy?
Can't answer the corn starch question - never tried it. But, yes, injection is not necessary if you brine. Although some inject different flavor ingredients after brining, but I don't. There really aren't any rules!
I brined a pork loin and injected one half with a butter flavored injection and the other half left plain. Both halves were equally juicy but I liked the extra flavor profile of the injection. I haven't tried a whole turkey yet.