Take your first example: the music festival promoter shows up at his bank with a duffel bag of cash -- that's not unusual until suddenly every single missing serial number lights up the bank's cash handling systems.
Busted.
It's possible to launder marked cash, but it has to be in such small quantities that it's always plausible that it was simply spent in circulation, which in practice dramatically limits the speed with which it can be laundered.
Probably the single most straightforward approach to dispose of marked bills would be to swap for unmarked cash with someone who doesn't care, like an overseas drug lord. But man, good luck with that.