If a grain has a fault, it needs to be put back in order. Grains must be perfectly identical at all times, otherwise they'll be thrown out. That's why special people will go out and check them to confirm their regularity. Keeping order is a tough job!
You can always tell if a company keeps order or if it cheats (ちつ) just by looking at the grains.
Currently there are no similar looking kanji which exist in the WaniKani learning system