You people keeping a bit, are you just hoping the amount you kept is small enough to not make it worth the time for repercussions?
If you took the cash and stashed it in your home, what’s the repercussions? Wait it out a year and see if there’s any activity around it.
To me, the biggest issue is how to spend it without the IRS getting interested. You’ll need to start some sort of service business to launder it slowly.
But it isn’t keeping the money that gets you in trouble, it’s spending it.