This article from the IHR is a bit of an introduction to the propaganda operations from the British during ww2.
https://ihr.org/journal/v18n5p15_propaganda.html
One of the most malicious PWE reports was this April 1943 story: “On entering Tunis Allied troops found dead children cut up as butchers’ meat in the German army store. Portions of them had already been used as pork ration. Typically enough, the Germans had filed their identity cards.”
There are of course many, many more.
The British 'venom campaign'
The British 'venom campaign'
were to guess why no t4 personnel were chosen to perform gassing that had experience with gassing, it would be because THERE WERE NONE.
Re: The British 'venom campaign'
The same regurgitation of the First World War, the Germans are Huns, they use whatever they can to create substitute products, they use blood serum in boiling pots to make soap. This is inherent to Germany, it will always be there as long as it is seen as the wrong side of history, while it is more difficult for Russians or Americans to have these allegations since they have apparently inexhaustible resources, but for Germany it is considered plausible, after all they go to war to obtain these raw materials, so they need to use what they have at hand.