This is an English dub of the eternal jew. I present it here as a snippet of history. Many questions are asked with regard to 'why did the Germans think (x)' or 'who did (y)'. This is a decent presentation of the German opinion on matters.
Take the dub with a grain of salt, as some liberties were taken. None the less, for what it is worth, here it is.
were to guess why no t4 personnel were chosen to perform gassing that had experience with gassing, it would be because THERE WERE NONE.