Nice of the SS to demonstrate the process for him. Please cite something in the original post to confirm that the showers had been used. The carnage Morin witnessed was not the result of business as usual in the camp. It was the hurried execution of prisoners to hide their very existence from liberating forces. Certainly the “showers” would have been used, but nothing I read in the post indicates that they had been. Gitmo may be able to provide citation for his/ her claim.
Per my post 35 above, a German historian and guide at Dachau explained to me how the SS used Dachau to test out prototype gas chamber systems and processes. It was there that they determined that camouflaging the gas chambers as showers was the most effective way to get the prisoners into the chamber without a fight. To be clear, thousands of prisoners died as part of these tests.
Perfecting the execution mechanisms and processes for the actual death camps was part and parcel of the Dachau camp’s “business as usual.”