I grill a lot and marinades penetrate the meat before cooking. That's why they have agents like vinegar, wine, citrus fruit juice that brake the fibers and, if you may, drag along the flavors with them inside the meat. I find it works best on poultry. I'm new to smoking but I'm assuming that the low and slow, as opposed to fast grilling, favors rubs where the fat drags the flavors into the meat over a longer period. That didn't stop me from smoking marinated or brined chicken with excellent results thus far. That is 2 for 2. LOL