Headscratchers / Wool

• We're told that everyone who has ever been sent to clean has actually gone ahead with it, because there's a screen in their helmet that makes them think the world is beautiful, and they're all so happy to see a beautiful world that they end up pitying the people in the silo and thus they're happy to clean the sensors for them. But wouldn't there be at least one guy who's so distracted by the virtual view that he decides to walk around for twenty minutes before cleaning, and thus winds up dead before he ever gets to the job?
  • In the show version, it’s made clear that sometimes people don’t clean the sensors. The people in the Silo just can’t do anything about it and the sensors just stay kinda dirty until the next person cleans them.
  • It's possible that there's something in the suit's air supply (or maybe something they slip into the cleaner's last meal, or something like that) that makes the person fixate on the objective of cleaning. Allison does point out that "everyone" does wind up cleaning, even the people who were sent out as execution for another crime and had no interest in the outside world. That seems to suggest that IT is "encouraging" them in that direction.
  • In the TV adaptation, the mayor's speech to the future cleaner includes the phrase "I hope that you do clean, so that the people of the Silo can see our world for what it is." We also hear a bit of audio from a past cleaning, and the cleaner (seemingly thinking that the headset has a microphone or something) saying repeatedly "guys, you gotta see this." That little speech seems to be intentionally planting the idea that cleaning will reveal the truth to the people inside—which of course it does, just not the truth the cleaner thinks they're revealing—which is why so many people go through with it.

• The Order states "In the event of a failed cleaning, prepare for war". But why would a failed cleaning lead to war? Just because some guy refuses (or fails) to clean the sensors doesn't mean that the whole world is secretly tyrannical and you need to stage a rebellion. All it means is that one random guy was too stubborn (or incompetent) to clean the sensors. It only worked in Juliette's case because Walker had swapped out the suit and Juliette survived and Walker was able to explain to everyone how IT had been pulling the strings the whole time. Most other failed cleanings wouldn't have those extra features.
  • The Order was written by paranoid control freaks. In their minds, a cleaning could only fail if it had been sabotaged, which could only happen if the truth behind IT and by extension the Silos were either exposed or about to be.
  • Perhaps the Order is speaking more generally than the idea of one guy deciding not to clean a camera sensor. "Failed cleaning" could very well be referring to the case of the cleaner surviving, like Juliette did. If someone manages to come back in, all bets are off, and IT is clearly going to great lengths to avoid that happening. Or the condemned cleaner-to-be putting up a fight, perhaps a successful fight, on the way out. Or the other people in the Silo deciding that this person has been wrongfully condemned and putting up a fight of their own. "Failed cleaning" is a very big phrase that covers a lot of potential catastrophes.