That would pretty much be the antithesis of barbecue, which, as we know, is the practice of cooking:
* typically (but not limited to) less-than-tender cuts of meat,
* at low temperatures, between 212 and 250 degrees Fahrenheit,
* for long cooking times, usually four or more hours,
* preferably over a charcoal, or wood coal fired, indirect heat source,
* typically including the additional burning of smoke woods to impart certain desired flavor characteristics,
* the end result being tender and flavorful in a way not possible using higher temperatures and shorter cooking times.
What's in your pantry is likely Adolph's or something similar, which contains papain, a proteolytic enzyme derived from papaya. It also likely contains MSG. "Proteolytic" means, literally, "breaks down protein", which means it will also work favorably on a variety of snake venoms. Enzymes found in pineapple have a similar effect, and are the reason Jello recipes specify not to add the fresh or frozen fruit to unset gelatin.
To answer your question: I think if you added it to your rub, much of what you barbecued would be unacceptably mushy.
