So I bought an old one gallon brown glass growler off kijiji. It still has the label on it, which says it's the "finest Norwegian cod liver oil." My idea was to use it as a bright tank for small experimental batches, because the amber colour would keep the hops from going skunky if I age it a long time before bottling. It came with about four inches of sludge in the bottom - congealed cod liver oil, I'm guessing by the antique label to be at least fifty years old.
Cod liver oil smells bad enough when it's fresh, so I can't even begin to describe how ghastly an odour was emanating from that bottle when I opened it. Then when I added hot water to help loosen up the blob, all the aromatic compounds that had been aging to perfection for decades began wafting through my kitchen, permeating deep into the fabric of my soul. Now I'm being haunted by the ghosts of a thousand codfish.
I loosened up most of the solids inside while managing to supress a gag reflex, and then filled it with bleach and hot water. Then I shook it out and filled it with hot water and dish detergent, hoping the surfactant will strip it down to glass. I left it overnight and I plan to replace it again with bleach-water to (ohpleaseohpleaseohplease) get rid of the smell.
My wife was appalled to say the least when she returned home to have her nostrils inundated with rancid fish stink. I assured her I would take care of it, though I'm not entirely sure how. My main concern right now is the jug, then I'll deal with the smell in the house.
I've done lots of canning and found that some food leaves a smell in the mason jars even after multiple cleanings, but it's never been strong enough that it's affected subsequent canning batches, so I've never bothered trying bleach. I'm concerned about imparting a foul fish liver smell to my beer, but I've suffered too much for this cause to just give up now and throw the jug away.
If anybody has had a similar experience and successfully eradicated the smells/tastes, I enthusiastically welcome your shared knowledge and wisdom. Otherwise, please feel free to have a good laugh at my expense.