Ah I get it. Only you know the proper sequence. Whatever order the washers are when you collect them, you know how to rearrange them. So there’s a small portion of your seed phrase that is in your mind (the sequence).
Discussion
Aha! It's pretty trivial to just try all possible combos, but average person that would know what to do with a seed phrase would not go past the "Well I entered this seed and ain't shit here!" phase.
It’s a clever way to create a plausible deniability seed phrase. The answer is in there somewhere, they just have no idea