Yeah, j, I think many glom onto this notion or that (because this one one that one does this or that and they win) without understanding what is going on. Many 'masters' do not understand it either. I'd argue that Lilly's injecting his pork was not the secret to his wins, it was what the injection did - and, no, 'moisture' has nothing to do with it. Regardless, anything you can do with an injection prior to cooking you can do after cooking (and thus I don't bother), provided the meat will be pulled, chopped, or sliced thinly, and provided it is correctly cooked. Nothing wrong with injecting though - or brining - and both
can offer some leeway in terms of finish, i.e., both can widen the 'done' window. Anyway...
Marty- Brines are not suitable for adding to the meat after cooking, nor are most injections. For that you need a finishing sauce The one I use is
here. I like it because it works well to even out texture and flavor, and it goes well with whatever sauce I will be serving with the pork; others like other types of finishing sauces. The operative variables are that it is relatively thin so that it distributes well, yet relatively viscous (via emulsification or an added thickener/stabilizer) so that it clings well. Imo, it is a good idea if its color reads as fairly neutral once on the meat.
Your ratio would be fine. You could even up the salt if you wish.
One simply injects evenly all over the butt(s), starting with the needle totally plunged into the flesh, and injecting the solution as the needle is drawn out. Many cooks like to wrap their roasts in plastic first and plunge the needle through the plastic. Bit less potentially messy this way.
If you go to the Pork Recipes section toward the bottom of the main Forum page and click there, then scroll down on the next page, you will find Chris Lilly's injection listed. Try it, try your own, see what you think.
(Btw, I pull and chop at the same time when I do butts. The meat comes out as a combination of the two, mixed together, but the strands of the pulled portion are quite short. Never much cared for the texture or appearance of straight pulled pork.)
Experiment and have fun with it.