No, I'm not saying the workers at 231's installation didn't lose their memories, I'm just saying it wasn't done simply by injection. Memories can still be erased in my world, just not as easily, although i do think it would go rather smoothly if 1) they willingly wanted to forgot and 2)they went under a rigorous hypnosis session before arriving, one that later could be triggered making them believe something else. If you could put a mental block in before something happened, I'm pretty sure it could be covered up quite well, in comparison to first receiving treatment afterwards. (the mental suggestion would be before and then if they wanted a cover story, they would have it activated after, as opposed to going in with nothing in place)
It's like this:
Termination=Death
Monthly rotation of Class D Personnel: gassing thirty prisoners every month
Class A Amnesiac= long process that on the willing involves hypnotic blocks and on the unwilling entails mental and physical torture
And like I said before, this twist wasn't originally my main point,i just realized i had to explain it somehow if i wanted to include torture scenes, which i thought was the only way to do it because
1)more visceral and dramatic
2) it just didn't make sense to me to have the people freak out around Glut if they didn't undergo something as traumatic as torture, as opposed to the relatively gentle action of injection, and this freaking out was needed to que that something was going wrong
Now my intention is people read about class As, find them rather innocent, just a throw aside reference causing no trouble, put it in the back of their head, and then read this and learn that it's not a humane method, The Foundation is still doing it rather primitively and horribly, and they're lying to themselves and other more naive personnel (like the cubicle dwellers who write the SCP reports), implying that there are even more terrifying truths hidden in seemingly safe phrases and sentences.