For the butt: Try 1 cup apple juice, 3-4 tbs soy sauce - and some of a low salt rub dissolved in it. Strain and inject after chilling the liquid to approx. 40F or lower. This is a food safety issue. Cold meat, cold injection. back into the fridge until ready to cook.
For the turkey: Good ole chicken broth with a touch of soy sauce is a good start for an injection. Same food safety rules apply here as for temperature.. Rub the exterior with siracha, or butter with herbs ( rosemary, sage, thyme ) - your choice.
Let us know how it turns out!
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