57 years old, and I’ve lived in the US all my life. I still hear “fifth” used to denote the 750ml bottle all the time, and I use it myself. But, like you, I’ve never seen an actual “fifth” (at least not since liquor went metric, which would be sometime after I was old enough to buy booze) – just the 750ml bottle. I don’t think anyone bottles liquor in the old units anymore.
I’d also advise if you’re going to try this, don’t do it on an empty stomach.
Put whatever you want on it – if all you want is bacon and bread, go for it.
Ever do a pickle-back? A shot of crap whiskey, followed with a shot of pickle juice. It’s freaky. You do not taste the whiskey at all. 
Those are surprisingly better than they ought to be. They also set up shooting at a rate guaranteed to overshoot your tolerance. Leading to incoherence, unconsciousness, or worse.
By “worse”, I assume you mean pickle-breath.
ANd if you never knew that the pot had been used to hurl into, you would have no issues at all. Sheesh. I also would bath my younger goddaughters in the kitchen sink when they had a particularly bad diaper poo blowup [sprayer is wonderful for hosing off little butts] It isn’t like I didn’t clean thoroughly afterwards. Stainless steel + comet cleanser = pretty damned sterile.
But I like the taste of whiskey, and don’t drink crap whiskey! 
I’ve never been anywhere that I knew this was on offer. I think in theory I have heard of it before, but not in practice. Closest I’ve come is chasing vodka with pickled herring.
a former GF told me her previous BF drank about a bottle a day of whiskey. I guess he was drinking cheap stuff since that could add up fast.
Of course it’s dangerous! I would certainly classify drinking a fifth of alcohol in one day as a high-risk activity, not just from the obvious health point of view either. You could fall and hurt yourself, if drinking with others someone could turn violent, you might say something out of turn at the Women’s Institute, you could crash the plane, or shout ‘PIG!’ at a policeman and be shot on sight.
I just remembered that the protagonist of Larry Niven’s “Inferno” dies (in the first chapter; it’s not a spoiler) from chugging a fifth of rum. Of course, he’s sitting on a window ledge at the time, and it’s the fall that kills him.
Also, here’s a website on how to get the vomit smell out of stuff.
I don’t drink as much as I used to but I can go through half a fifth of scotch without skipping a beat. If I had the whole bottle these days, I would likely black out but there was a time, when I was in my prime when I could really throw it down.
I’m not the smallest guy at 5’6 210. However, me and my liver have had a love hate relationship since I turned 16. I remember getting so drunk that I passed out taking a piss for 2 hours while my friends and family went on a full out search I woke up with my d**k still in one hand and a bottle in the other face down in the grass. Not a fun time. I say that to say this I drink about once a month and when I do I’ll drink a fifth in about two to three hours I don’t black out or do stupid shit like Passout in a puddle of my own piss lol. Sure I wake up with a hangover from hell and swear to myself never to drink again but I’ve never had any health related issues or scares. If you are asking this shortly after consuming this amount know that if you are able to ask the internet you are doing better than most lol.
6’-0" 185. Mid fifties - high tolerance to alcohol. Never done a fifth in one go though.
Probably over two nights in the comfort of my home - bourbon mixed with coke.
Be careful out there.
That is called a binge-type alcoholic. As compared to the daily-drinker type, who drinks a smaller amount, but does so every day (or most days, or every weekend).
We prefer that old threads only be bumped to provide new factual information. Since this has been bumped just to provide anecdotal information, and the actual question was answered 14 years ago, I’m closing this.
Colibri
General Questions Moderator