I would think it would be worth losing a slight amount of BBQ sauce on the side of the jug versus watering down your favorite sauce to get it all out.
It's actually a concentrate. The instructions say to add 2 quarts of water and a pound of brown sugar to the gallon of concentrate. My family, growing up, never added anything and enjoyed the concentrated sauce.
If you do it according to instructions, it turns out to be a clone for Dreamland's sauce.