I found some DIY directions, but according to the wiki "older bars" are happy to conduct the ceremony.
Here is what wikitravel had to say: The use of an actual fish is rare, though, especially since the introduction of the cod moritorum. Kissing a real codfish is discouraged by many, not to mention possibly unhygienic, so an imitation cod, made of wood, plastic, or rubber is used.
"small 'squid' with shape like a pouch. usage: '1968 Mercer 1 Squids of this genus (Rossia palpebrosa) are small ... and have a bursiform configuration, leading to such names as 'bottleass squid' and 'purse squid' in Newfoundland. P 1–75 Bottle-ass squid is commonly used among some fishermen." —Dictionary of Newfoundland English, 58