Adding a liquid such as Beef stock, beer or whombat piss either as an injection or in a foil pouch won't make any piece of meat moist! The moisture comes after all the water has been squeezed out during the cooking process and the collagen( the stuff that holds the muscle fibers together) melts and turns into Gelatin. It is the Gelatin that is what is associated with a moist piece of meat. This starts to happen at about 180 deg ( at the end of a stall) it is in full swing by 190 and drops off after 210 unless it was an old critter then It can go past 220. The longer the brisket stays in this range the better up to a point. I find that once a brisket becomes probe tender it it is allowed to rest wrapped in a single layer of Butcher paper or Loosely tented with foil on the counter the better the moisture content. as it slowly cools the meat relaxes once the temp gets into the 150 deg range the gelatin begins to thicken slightly.IMHO this is the optimal time to slice only what you need and serve. When you slice up the whole thing you loose gelatin on the board and your slices will dry out especially when reheating due the increased surface area.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC