Technically, it never says anything about it directly, but you most likely can't. Since it defines what a paintball gun is most likely your mouth doesn't fit that description and blowing paintballs out is most likely illegal.
However, you can't leave any of your equipment behind.
The rules concerning equipment basically break down like this:
You are required to keep your gun and the rest of your equipment with you, since all of your stuff is counted as "you" and if it gets shot you're out. The only time you can shed a piece of your equipment is a pod which must touch the ground before it is considered out of play.
Also, I believe there is a max length you are allowed to be away from your equipment, if you go beyond that you're considered out.