Codswallop isn't nonsense, it's bullshit.

David J.C. McKay in his book titled "Sustainable Energy -Without hot air" , a good book btw, uses "codswallop" as in, "Companies also contribute to the daily codswallop as they tell us how wonderful they are."

'Codswallop'. 'Codswallop', 'Codswallop', I love that word. My Kindle dictionary says it is informal British for 'nonsense.' But 'codswallop' is so much more powerful to me than 'nonsense'. I think it would be a good substitute for 'bullshit' when you're in company you don't want to offend.