One interesting thing about word origins is how they’re always opposite of how the word is used by any sensible person today, but I don’t want to mention that, so please ignore it. What I was thinking of was minced oaths, which is what you get when you out with a swear, chop it up into fine bits, mix it with blackberries and enough sugar to bury a parking garage and bake it into a pie. These are traditionally softer and less offensive than the original swearing stuff, but no less usable as a thing to say, and they have interesting origins behind them.
Consider “Gadzooks”, for example. This is a corruption of the original, “God’s Zunes,” which reflect the deity’s strong belief in the Zune. “I mean, Microsoft has more money than me,” He was quoted as saying. “How could they not sell an MP3 player, for my sake?” At press time, God was saying he felt very confident about the new line of Blackberry thingies.