Here's your (insensitive and horrible) word list. You've been warned.
Everyone gets their preferred version of the F-word for free, plus a randomly-chosen assortment of other words.
What, you're still here? That was the joke.
Okay, fine, let's pretend I'm serious, as I really do enjoy a good game of Og now and again. Instead of being stupid cavemen, the PCs are fuckin' drunken cowboys. So you use the existing Og rules with a few simple modifications. You'd rename most things, and have to create a few mechanics. Eloquent Caveman becomes Cussin' Cowboy (or perhaps Fuckin' Wordy Cowboy), for example. And it might be worth creating a new class for Sober Cowboy who never forgets how to do things, though I'd strictly limit that class to one PC per campaign.
You'll need twice as many words per character, so 2d6+4 per PC, and the Fuckin' Eloquent Cowboy gets 4 more than anyone else rolled, plus all 4 versions of fuck on top of that. PC's names are of course not on the list, but I'm sure you'll come up with nicknames from your word list.
You have guns, so damage is 1 for a punch (2 for Strong Cowboy) and 1d6 for a gunshot, reversing the default Og unfairness (where Banging isn't nearly as good a Strong). That's a much faster and bloodier combat system too, and all the more so because there's no 40-Unnnggh T-Rex's to deal with. All of which is okay as the length of combat is at times somewhat unfortunate in Og. Replace your dino and mega-fauna monster list with miners, cardsharps, goons, saloongirls and railbarons.
The hardest part would be making the economy work. Og has no economy, but Deadwood is all about the gold in them thar hills. So you let gold buy guns, property, booze and whores, all of which need mechanical benefits. Guns = damage boosts, obviously, and the others could all be mechanisms for restoring Unnnggh, or might give some other bonus (like adding +1, or rolling two dice and keeping the better one). Giving them all mechanical benefits gives the PCs something to fight over, which is kinda the point. So these resources need to be limited and tightly controlled by the GM. The system becomes crunchier than default Og, but characters die so fast once the guns come out that I don't think you'll really feel the heft of the crunch. Some groups will have so much fun cussin' up a blue streak that they won't ever roll the dice.
I just thought up the marketing pitch: "No use big words, fuck Og." :)