Start by mixing rub ingredients together in a small bowl. Place corned beef on a large sheet of foil, spread the rub on all sides of the corned beef. Wrap in corned beef in the foil, then wrap again three times more.
Place the corned beef in the slow cooker, no water is added. Place lid on slow cooker.
Slow cook on LOW for 7- 8 hours without opening the lid.
Take the corned beef out, leaving in the foil let it rest, on a cutting board, while you prepare the coleslaw, and russian dressing, about 20 minutes.
Prepare coleslaw dressing by stirring all the coleslaw dressing ingredients together in a small bowl. I only toss a little dressing with the amount I of coleslaw I need at the moment, since there is just 2 of us, I like to keep it crisp.
Prepare the Russian Dressing by mixing the ingredients together is a small bowl.
Open the foiled corned beef, and dump out the juices, I didn't save these juices, I found no need for them.
Slice the corned beef, and prepare your sandwiches.
Butter the marble rye and brown them in a skillet.
Spread the russian dressing on the bottom piece.
Pile up the corned beef next.
Swiss cheese next.
Top piece of marble rye, secured with toothpicks if desired, and cut in half.