I haven't used a jaccard on brisket or butt. Both of those cuts generally have plenty of fat and cook long enough to make them tender. With the brisket, I would think that you would lose too much moisture by working the meat with it, thus producing a dry finished product - but I may be wrong. I seem to have read that a jaccard will not dry out your meat...? If your meat is coming out less than tender, I generally chock that up to too little time cooking. You might also try foiling as an aid.