I had noticed one of the subs my Dad served on during the war, the Irex was commissioned this past week, 70 years ago.
I was over at his house last night and mentioned this to him, the Irex was in Portsmouth NH. He had told me about interring Uboats, he talked about how filthy they were (no latrines on board, the bilge was used to ‘store’ human waste).
He told me he was filmed on a newsreel boarding a Uboats, his mother went to the theatre multiple times to watch him in the newsreel. :D
U Boats had toilets but your Dad is not wrong with his memories.
The Toilet that Sank the U-1206
http://www.neatorama.com/2014/04/28/The-Toilet-that-Sank-the-U-1206/
Hope your dad had a peaceful and happy life after serving his country under very difficult and dangerous conditions. From what I have been told by guys who were there, life on those WWII era subs was no stroll in the park. One navy vet who I worked with a couple of decades after the war served on a Navy long range patrol boat operating out of an Alaska port. He said a US sub that he boarded while it was in port for some reason or other that I don't remember stunk so bad he almost tossed his cookies before he could get back off.