Chili Mix IN- 3OZ BAG
Although it was formulated for pork, it is also excellent on smoked salmon and even popcorn. It will flavor, color, and form a wonderful crust when cooked at low temperatures. Some of the pros leave their rub on overnight, sort of a dry marinade, that can work like a brine or a curing process. There is a reaction between the rub and the surface that helps form a nice crust(called bark), if the rub is on for at least two or more hours in the refrigerator. Others put the rub right on the meat and massage it in. While others lay down a vegetable oil or mustard or ketchup base first and sprinkle the rub on top. 
Mustard is water, vinegar, and maybe white wine with mustard powder mixed in. During the cooking process as the water steams off and drips away, the mustard powder remaining is miniscule. If you like having the mustard flavor, you will do much better by just sprinkling it directly on the meat before cooking.
We recommend using a cooking oil because it helps keep the meat from sticking to the grill surface and because most of the herbs and spices in our rub are oil soluble, not water soluble.
Far more important is what is in the rub than under the rub. So use whatever you want. Because of the sugar, make sure to COOK AT LOW TEMPERATURES! If you keep your rub in an air tight container, you can keep it for months. If it clumps, just chop it up or you can spread it on a baking sheet and put it in the oven at 250 degrees F for about 15 minutes. For most meats, sprinkle just enough on to color it. Not too thick, about 2 tablespoons per side of a large slab of St. Louis Cut ribs