I dunno. Maybe instead of simply replacing the one or two words that have edged out every other kind of swearing in the English language, we could try to revive the fine art of lengthy, creative, florid, swearing that still exists (I hear) in at least a few other major languages.

excrement's always popular of course, but it'd be better if more of our excrement phrases involved robot vacuum cleaners, half-digested balloons, the dung of exotic animals...

(shrugs)
I'm a novice at it myself, but I think with a bit of practice, it could be done! Every swear should leave an indelible mental image of unutterable horror ;)