Every dollar bill in your wallet has trace amounts of cocaine on it. They probably spent some time tucked in some dancers g-string too. All money is "dirty". It's just a question of how many times it needs to trade hands before we collectively agree to treat it as "clean" again.
Neither of the things you’ve described make money dirty. Just because a dollar bill comes into contact with cocaine (often in cash sorting machines in banks), it doesn’t mean that it is the proceeds of crime.
I think his point is that a sizable portion of physical cash is involved with crime, that's one of the benefits of using cash so it only stands to reason- Yet everybody still uses cash regardless. Though I'm sure this same argument will be used in the future to justify a transition to a cashless society where all transactions are traced
