My first reaction was no, but I checked Google and there's quite a lot of info on there....

On the basis that it is one third of blood, fish and bone it wouldn't hurt but it needs to be diluted to the right level and it probably isn't a balanced feed on its own.

As Steragram says, plenty of info on the Internet. Though maybe there's a GoYer who actually uses it.

Instructions on how to make your own at http://www.ehow.com/list_7686402_fish-oil-good-fertilizer-garden.html (I think I would add a tight-fitting lid to the 5 gallon bucket - two week old decomposing fish is going to be pungent!)