Fill a balloon with grease, mud, gel, whatever you can get hold of that ahs that sort of consistancy. You don't want to stretch the balloon at all, just fill it a little, then tie a knot in the end.
Now take a pin and make, say, five holes in the surface of the balloon. Because you haven't stretched the surface, it shouldn't burst on you. Spread the holes out, don't bunch them together. Don't worry if a little of the goo you've placed inside leaks out, it's going to anyway.
Now, take the balloon in your hand, and squeeze it hard and fast. See how the goo squooshes out through all or most of the holes at once?
If you repeat the procedure you'll see that the amount is random. Some holes produce more on some tries that on others. Some will only leak a small amount of goo, while others will spray it far and wide.
Do I really need to explain the relevance of this any further?