As a kid I was fishing off the bribie island jetty and got hit by a catfish. An old timer next to me said he'd show me how to heal it immediately. He ripped the fish open and found the gall bladder, normally a bluey green sac behind the gut, then he squeezed the contents onto the stab site and the relief was immediate, effective and long-lasting. I do that whenever I now get jabbed which isn't often (older and wiser) with the big catties I get around Cairns. Same result, never even needed panadol, the pain and swelling just disappear. Might be a bit late for that now though. Another very effective remedy is to plunge the wound into almost boiling water which breaks the venom/slime down and reduces pain and swelling. Also not as messy as the gall bladder trick!