Btw, that ruleset doesn't have jokers.
4 jokers - for the first three who pick one up, you can put anything you want into the pint (dirty pint - we've had mixes of raw egg, yoghurt, whisky, brandy, lager, stout, gin, vodka, alcopops) The person who gets the last joker downs it.
If they don't down it, they don't play, ever again.
Also, we put the dirty pint (empty at the start) glass in the centre, not a shot glass.