I thought the point of laundering was that yes, you can see where every individual bitcoin goes, but that when you put it through a "washing" service it then goes to people who are completely unrelated to whatever Pablo was doing. And Pablo gets money that was completely unrelated to what he was doing, probably at another account.
a) Can the washing services "mix up" owners' address well enough that you can plausibly say, "I got money that was in a drug deal? Wow, only six thousand other people did too!" (I think they can.)
b) If a) is true, will it be plausible to ban washing services? They're pretty much the definition of money laundering, so the legal case is a lot more airtight.
