Chris
During the cooking the process, I spray the butts wth apple juice every hour or so after the first 5 hrs. Just a quick spray so the lid doesn't stay off long.
I mostly use sand in a foiled line pan with foil on top of the sand. Pan about 2/3 full. drippings will catch in it. With water in the pan, they just go into the water. I then skim off the fat/liquid the next day and put into frig. Turns into solid fat which I warm up and put on my dogs food - happy dog ! I don't need that extra fat so I don't use the drippings, it's not what you may think of as "meat juice".
After you pull the pork, I would remoisten with a liberal sprinkling of water over each layer in a pan, seal tightly with foil and then rewarm for about an hour in 300* oven. If you vacuum package, they can be rewarmed in the packages in boiling water.
Good luck.
Paul