Don't worry about sealing the holes I always have a cup or so of Aus Jus in the paper when I open it. The main Idea behind paper is it's porosity allowing it to breath but retain moisture without building up pressure and let smoke flavor in. When you wrap in foil it is like using a dutch oven the effect of the heat convects through it and nothing else as moisture is released into it it turns to steam increasing the thermal effects.This is why the bark goes soft and in some cases washes off.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC