well I just had to find out wha its all about.. so to quote
http://www.phrases.org.uk
"A load of codswallop" = Meaning Nonsense.
Origin
The origin of the term codswallop is unclear. The most widely quoted story has it that Hiram Codd, an English soft drinks maker during the 1870s...developed a technique for bottling lemonade....This process involved the insertion of a glass marble as a stopper into the neck of the bottle. When the bottle was shaken the resulting pressure from the fizzy pop forced the marble against the neck to form a seal. The device was called, not unreasonably, the Codd Bottle.
Wallop is a slang term for beer, and beer drinkers would certainly be disdainful of bottled soft drinks. It's not difficult to see how a soft drink in a Codd Bottle could have come to be called codswallop.
There's no actual evidence for that..... In fact neat plausibility without evidence is often ....known as folk etymology.
The earliest 'example phrase' in print is the script of a 1959 episode of the UK TV series 'Hancock's Half Hour'.....
....'A load of codswallop' sounds old and, interestingly, it is often used as 'a load of old codswallop'.
We also have the plausible and appealing Hiram Codd story.....Against that there's the entirely implausible notion that the phrase was in popular circulation since 1870 but somehow didn't manage to get into print until 1959.
The most likely explanation is that it is a made up word that just sounds right for its meaning.
Cod is a little-used slang word meaning 'to hoax or take a rise out of', known since at least 1873. It was used in much the same way we now use the verb 'to kid', as here in a quotation from 1884:
"Tha'st only coddin me as tha allus does; tha'l none tay me to see th' fair."
That could be the origin of the cod in 'codswallop', but that's just plausible speculation, which brings us back full circle.
I must look a bit of an "word anorack" (anorak is an innuit/Eskimo word=A heavy jacket with a hood)
....
but I just had to investigate