I cook picnics with the skin on. But, on the shoulder end, I use a boning knife held parallel to the meat to cut through the fat to separate the skin almost down to the joint. This allows me to peel back that flap of skin for applying rub onto the meat.
Then I just lay the skin back over and cook the picnic skin side up. I believe the skin helps to hold some fat and moisture in the meat as it cooks.
When the cook is finished, all the skin will slide right off without any delicate knife work.
I don't know how you're going to cook six picincs at one time on a Bullet. Even doing just four eight pounders, they'll likely have to be pretty cozy until they shrink down several hours into the cook.
You also probably ought to swap them top for bottom sometime toward the halfway point of the cook to even out their cooking times. Otherwise, the top ones will be done a few hours ahead of the ones on the cooler bottom grate.
20 hours seems reasonable for doing four eight pounders at once while still allowing a little fudge factor. Crowding six in there together is sounding less and less like a good plan. In addition to the extra time required due to the reduced circulation, all of your meat is going to spend a lot of hours at unsafe temperatures.
Is it really necessary to cook all of them at this time anyway? If you're feeding meat and side dishes to 30 normal men and women, the yield from three picnics would be roughly 12 pounds. At the four ounces per serving that's used as a ballpark figure, three picnics would feed everyone and still leave leftovers for snacking on.
Anyway, it's something to consider. Food for thought, I suppose.
