O.K. folks, I don't usually do anything but watch out for my own butt (and my buddy) on a dive, but here is one I heard about that seems harmless.
Canned Cheeze Whiz will not only perform like spray string (Kid's toy), but is enjoyed by most reef fish as it disintegrates.
Use your imagination! a small can smuggled down in a pocket can provide an unusual distraction to an ordinary dive if sprayed at an unsuspecting member of the group, in your own hair, etc. And as I said, the smaller fish in the reef will come out to enjoy every bit of this delicacy.
Dive safe, Airhead.